Finished Task 7: Observability

backend/go.work.sum

@@ -1,45 +1,46 @@
+cel.dev/expr v0.24.0/go.mod h1:hLPLo1W4QUmuYdA72RBX06QTs6MXw941piREPl3Yfiw=
+cloud.google.com/go/compute/metadata v0.9.0/go.mod h1:E0bWwX5wTnLPedCKqk3pJmVgCBSM6qQI1yTBdEb3C10=
+github.com/GoogleCloudPlatform/opentelemetry-operations-go/detectors/gcp v1.30.0/go.mod h1:P4WPRUkOhJC13W//jWpyfJNDAIpvRbAUIYLX/4jtlE0=
 github.com/alecthomas/kingpin/v2 v2.4.0/go.mod h1:0gyi0zQnjuFk8xrkNKamJoyUo382HRL7ATRpFZCw6tE=
 github.com/alecthomas/units v0.0.0-20211218093645-b94a6e3cc137/go.mod h1:OMCwj8VM1Kc9e19TLln2VL61YJF0x1XFtfdL4JdbSyE=
-github.com/alicebob/gopher-json v0.0.0-20200520072559-a9ecdc9d1d3a h1:HbKu58rmZpUGpz5+4FfNmIU+FmZg2P3Xaj2v2bfNWmk=
+github.com/antihax/optional v1.0.0/go.mod h1:uupD/76wgC+ih3iEmQUL+0Ugr19nfwCT1kdvxnR2qWY=
-github.com/alicebob/gopher-json v0.0.0-20200520072559-a9ecdc9d1d3a/go.mod h1:SGnFV6hVsYE877CKEZ6tDNTjaSXYUk6QqoIK6PrAtcc=
+github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
-github.com/alicebob/miniredis/v2 v2.33.0 h1:uvTF0EDeu9RLnUEG27Db5I68ESoIxTiXbNUiji6lZrA=
+github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
-github.com/alicebob/miniredis/v2 v2.33.0/go.mod h1:MhP4a3EU7aENRi9aO+tHfTBZicLqQevyi/DJpoj6mi0=
+github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
-github.com/bsm/ginkgo/v2 v2.12.0/go.mod h1:SwYbGRRDovPVboqFv0tPTcG1sN61LM1Z4ARdbAV9g4c=
+github.com/cncf/xds/go v0.0.0-20251022180443-0feb69152e9f/go.mod h1:HlzOvOjVBOfTGSRXRyY0OiCS/3J1akRGQQpRO/7zyF4=
-github.com/bsm/gomega v1.27.10/go.mod h1:JyEr/xRbxbtgWNi8tIEVPUYZ5Dzef52k01W3YH0H+O0=
+github.com/envoyproxy/go-control-plane v0.13.5-0.20251024222203-75eaa193e329/go.mod h1:Alz8LEClvR7xKsrq3qzoc4N0guvVNSS8KmSChGYr9hs=
-github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f h1:lO4WD4F/rVNCu3HqELle0jiPLLBs70cWOduZpkS1E78=
+github.com/envoyproxy/go-control-plane/envoy v1.35.0/go.mod h1:09qwbGVuSWWAyN5t/b3iyVfz5+z8QWGrzkoqm/8SbEs=
-github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f/go.mod h1:cuUVRXasLTGF7a8hSLbxyZXjz+1KgoB3wDUb6vlszIc=
+github.com/envoyproxy/go-control-plane/ratelimit v0.1.0/go.mod h1:Wk+tMFAFbCXaJPzVVHnPgRKdUdwW/KdbRt94AzgRee4=
+github.com/envoyproxy/protoc-gen-validate v1.2.1/go.mod h1:d/C80l/jxXLdfEIhX1W2TmLfsJ31lvEjwamM4DxlWXU=
+github.com/go-jose/go-jose/v4 v4.1.3/go.mod h1:x4oUasVrzR7071A4TnHLGSPpNOm2a21K9Kf04k1rs08=
 github.com/go-kit/log v0.2.1/go.mod h1:NwTd00d/i8cPZ3xOwwiv2PO5MOcx78fFErGNcVmBjv0=
 github.com/go-logfmt/logfmt v0.5.1/go.mod h1:WYhtIu8zTZfxdn5+rREduYbwxfcBr/Vr6KEVveWlfTs=
+github.com/golang/glog v1.2.5/go.mod h1:6AhwSGph0fcJtXVM/PEHPqZlFeoLxhs7/t5UDAwmO+w=
 github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
-github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
-github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
-github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 h1:iCEnooe7UlwOQYpKFhBabPMi4aNAfoODPEFNiAnClxo=
-github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
-github.com/jackc/pgx/v5 v5.7.2 h1:mLoDLV6sonKlvjIEsV56SkWNCnuNv531l94GaIzO+XI=
-github.com/jackc/pgx/v5 v5.7.2/go.mod h1:ncY89UGWxg82EykZUwSpUKEfccBGGYq1xjrOpsbsfGQ=
-github.com/jackc/puddle/v2 v2.2.2 h1:PR8nw+E/1w0GLuRFSmiioY6UooMp6KJv0/61nB7icHo=
-github.com/jackc/puddle/v2 v2.2.2/go.mod h1:vriiEXHvEE654aYKXXjOvZM39qJ0q+azkZFrfEOc3H4=
 github.com/jpillora/backoff v1.0.0/go.mod h1:J/6gKK9jxlEcS3zixgDgUAsiuZ7yrSoa/FX5e0EB2j4=
 github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
 github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
-github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
 github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/philhofer/fwd v1.1.2/go.mod h1:qkPdfjR2SIEbspLqpe1tO4n5yICnr2DY7mqEx2tUTP0=
-github.com/redis/go-redis/v9 v9.7.0 h1:HhLSs+B6O021gwzl+locl0zEDnyNkxMtf/Z3NNBMa9E=
+github.com/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10/go.mod h1:t/avpk3KcrXxUnYOhZhMXJlSEyie6gQbtLq5NM3loB8=
-github.com/redis/go-redis/v9 v9.7.0/go.mod h1:f6zhXITC7JUJIlPEiBOTXxJgPLdZcA93GewI7inzyWw=
+github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
+github.com/spiffe/go-spiffe/v2 v2.6.0/go.mod h1:gm2SeUoMZEtpnzPNs2Csc0D/gX33k1xIx7lEzqblHEs=
 github.com/stretchr/objx v0.5.2/go.mod h1:FRsXN1f5AsAjCGJKqEizvkpNtU+EGNCLh3NxZ/8L+MA=
 github.com/tinylib/msgp v1.1.8/go.mod h1:qkpG+2ldGg4xRFmx+jfTvZPxfGFhi64BcnL9vkCm/Tw=
 github.com/xhit/go-str2duration/v2 v2.1.0/go.mod h1:ohY8p+0f07DiV6Em5LKB0s2YpLtXVyJfNt1+BlmyAsU=
-github.com/yuin/gopher-lua v1.1.1 h1:kYKnWBjvbNP4XLT3+bPEwAXJx262OhaHDWDVOPjL46M=
+go.opentelemetry.io/contrib/detectors/gcp v1.38.0/go.mod h1:SU+iU7nu5ud4oCb3LQOhIZ3nRLj6FNVrKgtflbaf2ts=
-github.com/yuin/gopher-lua v1.1.1/go.mod h1:GBR0iDaNXjAgGg9zfCvksxSRnQx76gclCIb7kdAd1Pw=
+go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
 golang.org/x/mod v0.17.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
+golang.org/x/mod v0.31.0/go.mod h1:43JraMp9cGx1Rx3AqioxrbrhNsLl2l/iNAvuBkrezpg=
 golang.org/x/oauth2 v0.21.0/go.mod h1:XYTD2NtWslqkgxebSiOHnXEap4TF09sJSc7H1sXbhtI=
-golang.org/x/sync v0.10.0 h1:3NQrjDixjgGwUOCaF8w2+VYHv0Ve/vGYSbdkTa98gmQ=
+golang.org/x/oauth2 v0.34.0/go.mod h1:lzm5WQJQwKZ3nwavOZ3IS5Aulzxi68dUSgRHujetwEA=
-golang.org/x/sync v0.10.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.21.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.29.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.28.0/go.mod h1:Sw/lC2IAUZ92udQNf3WodGtn4k/XoLyZoh8v/8uiwek=
+golang.org/x/term v0.39.0/go.mod h1:yxzUCTP/U+FzoxfdKmLaA0RV1WgE0VY7hXBwKtY/4ww=
 golang.org/x/tools v0.21.1-0.20240508182429-e35e4ccd0d2d/go.mod h1:aiJjzUbINMkxbQROHiO6hDPo2LHcIPhhQsa9DLh0yGk=
+golang.org/x/tools v0.40.0/go.mod h1:Ik/tzLRlbscWpqqMRjyWYDisX8bG13FrdXp3o4Sr9lc=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=

backend/shared/go.mod

@@ -13,7 +13,11 @@ require (
 	github.com/prometheus/client_golang v1.20.5
 	github.com/redis/go-redis/v9 v9.7.0
 	github.com/rs/zerolog v1.33.0
-	github.com/stretchr/testify v1.10.0
+	github.com/stretchr/testify v1.11.1
+	go.opentelemetry.io/otel v1.40.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.40.0
+	go.opentelemetry.io/otel/sdk v1.40.0
+	go.opentelemetry.io/otel/trace v1.40.0
 )
 
 require (
@@ -21,18 +25,21 @@ require (
 	github.com/alicebob/gopher-json v0.0.0-20200520072559-a9ecdc9d1d3a // indirect
 	github.com/andybalholm/brotli v1.1.0 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cenkalti/backoff/v5 v5.0.3 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
 	github.com/gabriel-vasile/mimetype v1.4.8 // indirect
+	github.com/go-logr/logr v1.4.3 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/go-playground/locales v0.14.1 // indirect
 	github.com/go-playground/universal-translator v0.18.1 // indirect
 	github.com/gofiber/utils/v2 v2.0.0-beta.4 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.7 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
 	github.com/jackc/puddle/v2 v2.2.2 // indirect
 	github.com/klauspost/compress v1.17.9 // indirect
-	github.com/kr/text v0.2.0 // indirect
 	github.com/leodido/go-urn v1.4.0 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
@@ -45,12 +52,19 @@ require (
 	github.com/valyala/fasthttp v1.55.0 // indirect
 	github.com/valyala/tcplisten v1.0.0 // indirect
 	github.com/yuin/gopher-lua v1.1.1 // indirect
-	golang.org/x/crypto v0.32.0 // indirect
+	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
-	golang.org/x/net v0.34.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.40.0 // indirect
-	golang.org/x/sync v0.10.0 // indirect
+	go.opentelemetry.io/otel/metric v1.40.0 // indirect
-	golang.org/x/sys v0.29.0 // indirect
+	go.opentelemetry.io/proto/otlp v1.9.0 // indirect
-	golang.org/x/text v0.21.0 // indirect
+	golang.org/x/crypto v0.47.0 // indirect
+	golang.org/x/net v0.49.0 // indirect
+	golang.org/x/sync v0.19.0 // indirect
+	golang.org/x/sys v0.40.0 // indirect
+	golang.org/x/text v0.33.0 // indirect
 	golang.org/x/time v0.9.0 // indirect
-	google.golang.org/protobuf v1.34.2 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20260128011058-8636f8732409 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20260128011058-8636f8732409 // indirect
+	google.golang.org/grpc v1.78.0 // indirect
+	google.golang.org/protobuf v1.36.11 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

backend/shared/go.sum

@@ -3,23 +3,34 @@ github.com/MicahParks/jwkset v0.11.0/go.mod h1:U2oRhRaLgDCLjtpGL2GseNKGmZtLs/3O7
 github.com/MicahParks/keyfunc/v3 v3.7.0 h1:pdafUNyq+p3ZlvjJX1HWFP7MA3+cLpDtg69U3kITJGM=
 github.com/MicahParks/keyfunc/v3 v3.7.0/go.mod h1:z66bkCviwqfg2YUp+Jcc/xRE9IXLcMq6DrgV/+Htru0=
 github.com/alicebob/gopher-json v0.0.0-20200520072559-a9ecdc9d1d3a h1:HbKu58rmZpUGpz5+4FfNmIU+FmZg2P3Xaj2v2bfNWmk=
+github.com/alicebob/gopher-json v0.0.0-20200520072559-a9ecdc9d1d3a/go.mod h1:SGnFV6hVsYE877CKEZ6tDNTjaSXYUk6QqoIK6PrAtcc=
 github.com/alicebob/miniredis/v2 v2.33.0 h1:uvTF0EDeu9RLnUEG27Db5I68ESoIxTiXbNUiji6lZrA=
+github.com/alicebob/miniredis/v2 v2.33.0/go.mod h1:MhP4a3EU7aENRi9aO+tHfTBZicLqQevyi/DJpoj6mi0=
 github.com/andybalholm/brotli v1.1.0 h1:eLKJA0d02Lf0mVpIDgYnqXcUn0GqVmEFny3VuID1U3M=
 github.com/andybalholm/brotli v1.1.0/go.mod h1:sms7XGricyQI9K10gOSf56VKKWS4oLer58Q+mhRPtnY=
 github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/bsm/ginkgo/v2 v2.12.0 h1:Ny8MWAHyOepLGlLKYmXG4IEkioBysk6GpaRTLC8zwWs=
+github.com/bsm/ginkgo/v2 v2.12.0/go.mod h1:SwYbGRRDovPVboqFv0tPTcG1sN61LM1Z4ARdbAV9g4c=
 github.com/bsm/gomega v1.27.10 h1:yeMWxP2pV2fG3FgAODIY8EiRE3dy0aeFYt4l7wh6yKA=
+github.com/bsm/gomega v1.27.10/go.mod h1:JyEr/xRbxbtgWNi8tIEVPUYZ5Dzef52k01W3YH0H+O0=
+github.com/cenkalti/backoff/v5 v5.0.3 h1:ZN+IMa753KfX5hd8vVaMixjnqRZ3y8CuJKRKj1xcsSM=
+github.com/cenkalti/backoff/v5 v5.0.3/go.mod h1:rkhZdG3JZukswDf7f0cwqPNk4K0sa+F97BxZthm/crw=
 github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
 github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
-github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f h1:lO4WD4F/rVNCu3HqELle0jiPLLBs70cWOduZpkS1E78=
+github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f/go.mod h1:cuUVRXasLTGF7a8hSLbxyZXjz+1KgoB3wDUb6vlszIc=
 github.com/gabriel-vasile/mimetype v1.4.8 h1:FfZ3gj38NjllZIeJAmMhr+qKL8Wu+nOoI3GqacKw1NM=
 github.com/gabriel-vasile/mimetype v1.4.8/go.mod h1:ByKUIKGjh1ODkGM1asKUbQZOLGrPjydw3hYPU2YU9t8=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
+github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
 github.com/go-playground/assert/v2 v2.2.0 h1:JvknZsQTYeFEAhQwI4qEt9cyV5ONwRHC+lYKSsYSR8s=
 github.com/go-playground/assert/v2 v2.2.0/go.mod h1:VDjEfimB/XKnb+ZQfWdccd7VUvScMdVu0Titje2rxJ4=
 github.com/go-playground/locales v0.14.1 h1:EWaQ/wswjilfKLTECiXz7Rh+3BjFhfDFKv/oXslEjJA=
@@ -35,20 +46,30 @@ github.com/gofiber/utils/v2 v2.0.0-beta.4 h1:1gjbVFFwVwUb9arPcqiB6iEjHBwo7cHsyS4
 github.com/gofiber/utils/v2 v2.0.0-beta.4/go.mod h1:sdRsPU1FXX6YiDGGxd+q2aPJRMzpsxdzCXo9dz+xtOY=
 github.com/golang-jwt/jwt/v5 v5.2.2 h1:Rl4B7itRWVtYIHFrSNd7vhTiz9UpLdi6gZhZ3wEeDy8=
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-github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
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 github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
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 github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 h1:iCEnooe7UlwOQYpKFhBabPMi4aNAfoODPEFNiAnClxo=
+github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
 github.com/jackc/pgx/v5 v5.7.2 h1:mLoDLV6sonKlvjIEsV56SkWNCnuNv531l94GaIzO+XI=
+github.com/jackc/pgx/v5 v5.7.2/go.mod h1:ncY89UGWxg82EykZUwSpUKEfccBGGYq1xjrOpsbsfGQ=
 github.com/jackc/puddle/v2 v2.2.2 h1:PR8nw+E/1w0GLuRFSmiioY6UooMp6KJv0/61nB7icHo=
+github.com/jackc/puddle/v2 v2.2.2/go.mod h1:vriiEXHvEE654aYKXXjOvZM39qJ0q+azkZFrfEOc3H4=
 github.com/klauspost/compress v1.17.9 h1:6KIumPrER1LHsvBVuDa0r5xaG0Es51mhhB9BQB2qeMA=
 github.com/klauspost/compress v1.17.9/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
+github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
 github.com/leodido/go-urn v1.4.0 h1:WT9HwE9SGECu3lg4d/dIA+jxlljEa1/ffXKmRjqdmIQ=
 github.com/leodido/go-urn v1.4.0/go.mod h1:bvxc+MVxLKB4z00jd1z+Dvzr47oO32F/QSNjSBOlFxI=
 github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
@@ -71,16 +92,17 @@ github.com/prometheus/common v0.55.0/go.mod h1:2SECS4xJG1kd8XF9IcM1gMX6510RAEL65
 github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0learggepc=
 github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoGhij/e3PBqk=
 github.com/redis/go-redis/v9 v9.7.0 h1:HhLSs+B6O021gwzl+locl0zEDnyNkxMtf/Z3NNBMa9E=
-github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
+github.com/redis/go-redis/v9 v9.7.0/go.mod h1:f6zhXITC7JUJIlPEiBOTXxJgPLdZcA93GewI7inzyWw=
-github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
+github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=
+github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7so1lCWt35ZSgc=
 github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
 github.com/rs/zerolog v1.33.0 h1:1cU2KZkvPxNyfgEmhHAz/1A9Bz+llsdYzklWFzgp0r8=
 github.com/rs/zerolog v1.33.0/go.mod h1:/7mN4D5sKwJLZQ2b/znpjC3/GQWY/xaDXUM0kKWRHss=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
-github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 github.com/valyala/bytebufferpool v1.0.0 h1:GqA5TC/0021Y/b9FG4Oi9Mr3q7XYx6KllzawFIhcdPw=
 github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
 github.com/valyala/fasthttp v1.55.0 h1:Zkefzgt6a7+bVKHnu/YaYSOPfNYNisSVBo/unVCf8k8=
@@ -88,22 +110,52 @@ github.com/valyala/fasthttp v1.55.0/go.mod h1:NkY9JtkrpPKmgwV3HTaS2HWaJss9RSIsRV
 github.com/valyala/tcplisten v1.0.0 h1:rBHj/Xf+E1tRGZyWIWwJDiRY0zc1Js+CV5DqwacVSA8=
 github.com/valyala/tcplisten v1.0.0/go.mod h1:T0xQ8SeCZGxckz9qRXTfG43PvQ/mcWh7FwZEA7Ioqkc=
 github.com/yuin/gopher-lua v1.1.1 h1:kYKnWBjvbNP4XLT3+bPEwAXJx262OhaHDWDVOPjL46M=
-golang.org/x/crypto v0.32.0 h1:euUpcYgM8WcP71gNpTqQCn6rC2t6ULUPiOzfWaXVVfc=
+github.com/yuin/gopher-lua v1.1.1/go.mod h1:GBR0iDaNXjAgGg9zfCvksxSRnQx76gclCIb7kdAd1Pw=
-golang.org/x/crypto v0.32.0/go.mod h1:ZnnJkOaASj8g0AjIduWNlq2NRxL0PlBrbKVyZ6V/Ugc=
+go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
-golang.org/x/net v0.34.0 h1:Mb7Mrk043xzHgnRM88suvJFwzVrRfHEHJEl5/71CKw0=
+go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
-golang.org/x/net v0.34.0/go.mod h1:di0qlW3YNM5oh6GqDGQr92MyTozJPmybPK4Ev/Gm31k=
+go.opentelemetry.io/otel v1.40.0 h1:oA5YeOcpRTXq6NN7frwmwFR0Cn3RhTVZvXsP4duvCms=
-golang.org/x/sync v0.10.0 h1:3NQrjDixjgGwUOCaF8w2+VYHv0Ve/vGYSbdkTa98gmQ=
+go.opentelemetry.io/otel v1.40.0/go.mod h1:IMb+uXZUKkMXdPddhwAHm6UfOwJyh4ct1ybIlV14J0g=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.40.0 h1:QKdN8ly8zEMrByybbQgv8cWBcdAarwmIPZ6FThrWXJs=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.40.0/go.mod h1:bTdK1nhqF76qiPoCCdyFIV+N/sRHYXYCTQc+3VCi3MI=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.40.0 h1:wVZXIWjQSeSmMoxF74LzAnpVQOAFDo3pPji9Y4SOFKc=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.40.0/go.mod h1:khvBS2IggMFNwZK/6lEeHg/W57h/IX6J4URh57fuI40=
+go.opentelemetry.io/otel/metric v1.40.0 h1:rcZe317KPftE2rstWIBitCdVp89A2HqjkxR3c11+p9g=
+go.opentelemetry.io/otel/metric v1.40.0/go.mod h1:ib/crwQH7N3r5kfiBZQbwrTge743UDc7DTFVZrrXnqc=
+go.opentelemetry.io/otel/sdk v1.40.0 h1:KHW/jUzgo6wsPh9At46+h4upjtccTmuZCFAc9OJ71f8=
+go.opentelemetry.io/otel/sdk v1.40.0/go.mod h1:Ph7EFdYvxq72Y8Li9q8KebuYUr2KoeyHx0DRMKrYBUE=
+go.opentelemetry.io/otel/sdk/metric v1.40.0 h1:mtmdVqgQkeRxHgRv4qhyJduP3fYJRMX4AtAlbuWdCYw=
+go.opentelemetry.io/otel/sdk/metric v1.40.0/go.mod h1:4Z2bGMf0KSK3uRjlczMOeMhKU2rhUqdWNoKcYrtcBPg=
+go.opentelemetry.io/otel/trace v1.40.0 h1:WA4etStDttCSYuhwvEa8OP8I5EWu24lkOzp+ZYblVjw=
+go.opentelemetry.io/otel/trace v1.40.0/go.mod h1:zeAhriXecNGP/s2SEG3+Y8X9ujcJOTqQ5RgdEJcawiA=
+go.opentelemetry.io/proto/otlp v1.9.0 h1:l706jCMITVouPOqEnii2fIAuO3IVGBRPV5ICjceRb/A=
+go.opentelemetry.io/proto/otlp v1.9.0/go.mod h1:xE+Cx5E/eEHw+ISFkwPLwCZefwVjY+pqKg1qcK03+/4=
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+golang.org/x/net v0.49.0/go.mod h1:/ysNB2EvaqvesRkuLAyjI1ycPZlQHM3q01F02UY/MV8=
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 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.29.0 h1:TPYlXGxvx1MGTn2GiZDhnjPA9wZzZeGKHHmKhHYvgaU=
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 golang.org/x/time v0.9.0/go.mod h1:3BpzKBy/shNhVucY/MWOyx10tF3SFh9QdLuxbVysPQM=
-google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
+gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
-google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
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+google.golang.org/genproto/googleapis/api v0.0.0-20260128011058-8636f8732409 h1:merA0rdPeUV3YIIfHHcH4qBkiQAc1nfCKSI7lB4cV2M=
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+google.golang.org/genproto/googleapis/rpc v0.0.0-20260128011058-8636f8732409/go.mod h1:j9x/tPzZkyxcgEFkiKEEGxfvyumM01BEtsW8xzOahRQ=
+google.golang.org/grpc v1.78.0 h1:K1XZG/yGDJnzMdd/uZHAkVqJE+xIDOcmdSFZkBUicNc=
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+google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
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 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=

backend/shared/infra/observability/logging/logger.go

@@ -11,10 +11,15 @@ import (
 
 // Config holds the configuration for the logger.
 type Config struct {
+	// Level is the zerolog level string (e.g. debug, info, warn, error).
 	Level string
+	// Environment controls output format: development uses console, others use JSON.
 	Environment string
+	// ServiceName is injected in every log event as the service field.
 	ServiceName string
+	// Version is injected in every log event as the version field.
 	Version string
+	// Output defaults to stdout when nil.
 	Output io.Writer
 }
 
@@ -63,7 +68,7 @@ func NewLogger(config Config) *Logger {
 		logger = zerolog.New(output).With().Timestamp().Logger()
 	}
 
-	// Add service metadata
+	// Add service metadata to every log line.
 	logger = logger.With().
 		Str("service", config.ServiceName).
 		Str("version", config.Version).

backend/shared/infra/observability/logging/logger_test.go

@@ -30,3 +30,12 @@ func TestLogger_WithFields(t *testing.T) {
 	require.NotNil(t, withFields)
 	require.NotNil(t, logger.Zerolog())
 }
+
+// TestDefaultConfig_Stable verifies defaults remain unchanged.
+func TestDefaultConfig_Stable(t *testing.T) {
+	cfg := DefaultConfig()
+	require.Equal(t, "info", cfg.Level)
+	require.Equal(t, "development", cfg.Environment)
+	require.Equal(t, "knowfoolery", cfg.ServiceName)
+	require.Equal(t, "0.0.0", cfg.Version)
+}

backend/shared/infra/observability/metrics/http.go

@@ -0,0 +1,12 @@
+package metrics
+
+import (
+	"net/http"
+
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+// Handler returns a standard Prometheus metrics HTTP handler.
+func Handler() http.Handler {
+	return promhttp.Handler()
+}

backend/shared/infra/observability/metrics/http_test.go

@@ -0,0 +1,21 @@
+package metrics
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// TestHandler verifies Handler returns a usable HTTP handler.
+func TestHandler(t *testing.T) {
+	h := Handler()
+	require.NotNil(t, h)
+
+	req := httptest.NewRequest(http.MethodGet, "/metrics", nil)
+	rr := httptest.NewRecorder()
+
+	h.ServeHTTP(rr, req)
+	require.Equal(t, http.StatusOK, rr.Code)
+}

backend/shared/infra/observability/metrics/prometheus.go

@@ -2,8 +2,12 @@
 package metrics
 
 import (
+	"strconv"
+
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
+
+	"knowfoolery/backend/shared/infra/utils/envutil"
 )
 
 // Config holds the configuration for metrics.
@@ -204,6 +208,22 @@ func NewMetrics(config Config) *Metrics {
 
 // ConfigFromEnv creates a Config from environment variables.
 func ConfigFromEnv() Config {
-	// TODO: Implement environment variable parsing
+	cfg := DefaultConfig()
-	return DefaultConfig()
+	cfg.ServiceName = envutil.String("METRICS_SERVICE_NAME", cfg.ServiceName)
+	cfg.Enabled = parseBoolEnv("METRICS_ENABLED", cfg.Enabled)
+	return cfg
+}
+
+func parseBoolEnv(key string, fallback bool) bool {
+	value := envutil.String(key, "")
+	if value == "" {
+		return fallback
+	}
+
+	parsed, err := strconv.ParseBool(value)
+	if err != nil {
+		return fallback
+	}
+
+	return parsed
 }

backend/shared/infra/observability/metrics/prometheus_test.go

@@ -19,3 +19,24 @@ func TestNewMetrics_WithCustomRegistry(t *testing.T) {
 	require.NotNil(t, m.DBConnectionsActive)
 	require.NotNil(t, m.ScoreDistribution)
 }
+
+// TestConfigFromEnvDefaults verifies default env behavior.
+func TestConfigFromEnvDefaults(t *testing.T) {
+	t.Setenv("METRICS_ENABLED", "")
+	t.Setenv("METRICS_SERVICE_NAME", "")
+
+	cfg := ConfigFromEnv()
+	def := DefaultConfig()
+
+	require.Equal(t, def, cfg)
+}
+
+// TestConfigFromEnvOverrides verifies valid env overrides.
+func TestConfigFromEnvOverrides(t *testing.T) {
+	t.Setenv("METRICS_ENABLED", "false")
+	t.Setenv("METRICS_SERVICE_NAME", "admin-service")
+
+	cfg := ConfigFromEnv()
+	require.False(t, cfg.Enabled)
+	require.Equal(t, "admin-service", cfg.ServiceName)
+}

backend/shared/infra/observability/tracing/tracer.go

@@ -4,6 +4,19 @@ package tracing
 import (
 	"context"
 	"fmt"
+	"net/url"
+	"strconv"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
+	"go.opentelemetry.io/otel/sdk/resource"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
+	oteltrace "go.opentelemetry.io/otel/trace"
+
+	"knowfoolery/backend/shared/infra/utils/envutil"
 )
 
 // Config holds the configuration for the tracer.
@@ -11,6 +24,8 @@ type Config struct {
 	ServiceName    string
 	ServiceVersion string
 	Environment    string
+	OTLPEndpoint   string
+	// JaegerEndpoint is a deprecated legacy alias kept for backward compatibility.
 	JaegerEndpoint string
 	SampleRate     float64
 	Enabled        bool
@@ -22,6 +37,7 @@ func DefaultConfig() Config {
 		ServiceName:    "knowfoolery",
 		ServiceVersion: "0.0.0",
 		Environment:    "development",
+		OTLPEndpoint:   "http://localhost:4318/v1/traces",
 		JaegerEndpoint: "http://localhost:14268/api/traces",
 		SampleRate:     1.0, // Sample all traces in development
 		Enabled:        false,
@@ -29,43 +45,87 @@ func DefaultConfig() Config {
 }
 
 // Tracer provides distributed tracing functionality.
-// This is a placeholder that should be implemented with OpenTelemetry.
 type Tracer struct {
 	config   Config
+	provider *sdktrace.TracerProvider
+	tracer   oteltrace.Tracer
+	enabled  bool
 }
 
 // NewTracer creates a new Tracer.
-// Note: Actual implementation should use OpenTelemetry SDK.
 func NewTracer(config Config) (*Tracer, error) {
 	if !config.Enabled {
-		return &Tracer{config: config}, nil
+		return &Tracer{
+			config:  config,
+			tracer:  otel.Tracer(config.ServiceName),
+			enabled: false,
+		}, nil
+	}
+
+	sampleRate := config.SampleRate
+	if sampleRate < 0 || sampleRate > 1 {
+		sampleRate = 1.0
+	}
+
+	endpoint := config.OTLPEndpoint
+	if endpoint == "" {
+		endpoint = config.JaegerEndpoint
+	}
+
+	exporter, err := newOTLPHTTPExporter(endpoint)
+	if err != nil {
+		return nil, fmt.Errorf("create otlp exporter: %w", err)
+	}
+
+	res, err := resource.New(
+		context.Background(),
+		resource.WithAttributes(
+			semconv.ServiceName(config.ServiceName),
+			semconv.ServiceVersion(config.ServiceVersion),
+			attribute.String("deployment.environment", config.Environment),
+		),
+	)
+	if err != nil {
+		return nil, fmt.Errorf("create tracer resource: %w", err)
 	}
 
-	// TODO: Initialize OpenTelemetry tracer provider
+	provider := sdktrace.NewTracerProvider(
-	// Example implementation:
+		sdktrace.WithBatcher(exporter),
-	// - Create Jaeger exporter
+		sdktrace.WithSampler(sdktrace.TraceIDRatioBased(sampleRate)),
-	// - Create tracer provider with batching
+		sdktrace.WithResource(res),
-	// - Set global tracer provider
+	)
-	// - Configure resource with service info
 
-	return &Tracer{config: config}, nil
+	otel.SetTracerProvider(provider)
+
+	return &Tracer{
+		config:   config,
+		provider: provider,
+		tracer:   otel.Tracer(config.ServiceName),
+		enabled:  true,
+	}, nil
 }
 
 // Shutdown gracefully shuts down the tracer.
 func (t *Tracer) Shutdown(ctx context.Context) error {
-	if !t.config.Enabled {
+	if !t.enabled || t.provider == nil {
 		return nil
 	}
 
-	// TODO: Shutdown tracer provider
+	if err := t.provider.Shutdown(ctx); err != nil {
+		return fmt.Errorf("shutdown tracer provider: %w", err)
+	}
+
 	return nil
 }
 
 // StartSpan starts a new span.
-// This is a placeholder that should be implemented with OpenTelemetry.
 func (t *Tracer) StartSpan(ctx context.Context, name string) (context.Context, Span) {
-	// TODO: Start actual OpenTelemetry span
+	if !t.enabled || t.tracer == nil {
 		return ctx, &noopSpan{}
+	}
+
+	spanCtx, span := t.tracer.Start(ctx, name)
+	return spanCtx, &otelSpan{span: span}
 }
 
 // Span represents a tracing span.
@@ -85,6 +145,41 @@ func (s *noopSpan) End()                                       {}
 func (s *noopSpan) SetAttribute(key string, value interface{}) {}
 func (s *noopSpan) RecordError(err error)                      {}
 
+// otelSpan wraps an OpenTelemetry span with the local Span interface.
+type otelSpan struct {
+	span oteltrace.Span
+}
+
+func (s *otelSpan) End() {
+	s.span.End()
+}
+
+func (s *otelSpan) SetAttribute(key string, value interface{}) {
+	switch v := value.(type) {
+	case string:
+		s.span.SetAttributes(attribute.String(key, v))
+	case int:
+		s.span.SetAttributes(attribute.Int(key, v))
+	case int64:
+		s.span.SetAttributes(attribute.Int64(key, v))
+	case float64:
+		s.span.SetAttributes(attribute.Float64(key, v))
+	case bool:
+		s.span.SetAttributes(attribute.Bool(key, v))
+	default:
+		s.span.SetAttributes(attribute.String(key, fmt.Sprint(value)))
+	}
+}
+
+func (s *otelSpan) RecordError(err error) {
+	if err == nil {
+		return
+	}
+
+	s.span.RecordError(err)
+	s.span.SetStatus(codes.Error, err.Error())
+}
+
 // TraceServiceOperation traces a service operation.
 func TraceServiceOperation(ctx context.Context, tracer *Tracer, serviceName,
 	operation string, fn func(context.Context) error) error {
@@ -122,6 +217,85 @@ func TraceDatabaseOperation(ctx context.Context, tracer *Tracer, operation,
 
 // ConfigFromEnv creates a Config from environment variables.
 func ConfigFromEnv() Config {
-	// TODO: Implement environment variable parsing
+	cfg := DefaultConfig()
-	return DefaultConfig()
+
+	cfg.Enabled = parseBoolEnv("TRACING_ENABLED", cfg.Enabled)
+	cfg.ServiceName = envutil.String("TRACING_SERVICE_NAME", cfg.ServiceName)
+	cfg.ServiceVersion = envutil.String("TRACING_SERVICE_VERSION", cfg.ServiceVersion)
+	cfg.Environment = envutil.String("TRACING_ENVIRONMENT", cfg.Environment)
+	legacyEndpoint := envutil.String("TRACING_JAEGER_ENDPOINT", "")
+	if legacyEndpoint != "" {
+		cfg.JaegerEndpoint = legacyEndpoint
+	}
+	cfg.OTLPEndpoint = envutil.String("TRACING_OTLP_ENDPOINT", "")
+	if cfg.OTLPEndpoint == "" && legacyEndpoint != "" {
+		cfg.OTLPEndpoint = legacyEndpoint
+	}
+	if cfg.OTLPEndpoint == "" {
+		cfg.OTLPEndpoint = DefaultConfig().OTLPEndpoint
+	}
+	cfg.SampleRate = parseFloatEnv("TRACING_SAMPLE_RATE", cfg.SampleRate)
+
+	return cfg
+}
+
+func newOTLPHTTPExporter(endpoint string) (sdktrace.SpanExporter, error) {
+	parsed, err := url.Parse(endpoint)
+	if err != nil {
+		return nil, fmt.Errorf("parse endpoint: %w", err)
+	}
+	if parsed.Scheme == "" || parsed.Host == "" {
+		return nil, fmt.Errorf("endpoint must be absolute URL, got %q", endpoint)
+	}
+	if parsed.Scheme != "http" && parsed.Scheme != "https" {
+		return nil, fmt.Errorf("unsupported endpoint scheme %q", parsed.Scheme)
+	}
+
+	urlPath := parsed.EscapedPath()
+	if urlPath == "" || urlPath == "/" {
+		urlPath = "/v1/traces"
+	}
+
+	options := []otlptracehttp.Option{
+		otlptracehttp.WithEndpoint(parsed.Host),
+		otlptracehttp.WithURLPath(urlPath),
+	}
+	if parsed.Scheme == "http" {
+		options = append(options, otlptracehttp.WithInsecure())
+	}
+
+	exporter, err := otlptracehttp.New(context.Background(), options...)
+	if err != nil {
+		return nil, err
+	}
+
+	return exporter, nil
+}
+
+func parseBoolEnv(key string, fallback bool) bool {
+	value := envutil.String(key, "")
+	if value == "" {
+		return fallback
+	}
+
+	parsed, err := strconv.ParseBool(value)
+	if err != nil {
+		return fallback
+	}
+
+	return parsed
+}
+
+func parseFloatEnv(key string, fallback float64) float64 {
+	value := envutil.String(key, "")
+	if value == "" {
+		return fallback
+	}
+
+	parsed, err := strconv.ParseFloat(value, 64)
+	if err != nil {
+		return fallback
+	}
+
+	return parsed
 }

backend/shared/infra/observability/tracing/tracer_test.go

@@ -1,6 +1,6 @@
 package tracing
 
-// Tests for tracing helpers invoking operations and propagating errors.
+// Tests for tracing initialization, config parsing, and helper wrappers.
 
 import (
 	"context"
@@ -10,6 +10,45 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+// TestNewTracer_Disabled verifies disabled mode initializes and safely starts spans.
+func TestNewTracer_Disabled(t *testing.T) {
+	cfg := DefaultConfig()
+	cfg.Enabled = false
+
+	tracer, err := NewTracer(cfg)
+	require.NoError(t, err)
+	require.NotNil(t, tracer)
+
+	ctx, span := tracer.StartSpan(context.Background(), "test")
+	require.NotNil(t, ctx)
+	require.NotNil(t, span)
+	require.NotPanics(t, func() {
+		span.SetAttribute("k", "v")
+		span.RecordError(errors.New("boom"))
+		span.End()
+	})
+}
+
+// TestNewTracer_Enabled verifies enabled mode initializes tracer components.
+func TestNewTracer_Enabled(t *testing.T) {
+	cfg := DefaultConfig()
+	cfg.Enabled = true
+
+	tracer, err := NewTracer(cfg)
+	require.NoError(t, err)
+	require.NotNil(t, tracer)
+	require.NoError(t, tracer.Shutdown(context.Background()))
+}
+
+// TestShutdown_Disabled verifies shutdown is a no-op when tracing is disabled.
+func TestShutdown_Disabled(t *testing.T) {
+	tracer, err := NewTracer(DefaultConfig())
+	require.NoError(t, err)
+
+	err = tracer.Shutdown(context.Background())
+	require.NoError(t, err)
+}
+
 // TestTraceServiceOperation verifies tracing wraps a service operation and returns errors.
 func TestTraceServiceOperation(t *testing.T) {
 	tracer, err := NewTracer(DefaultConfig())
@@ -35,3 +74,67 @@ func TestTraceDatabaseOperation(t *testing.T) {
 	require.NoError(t, err)
 	require.True(t, called)
 }
+
+// TestConfigFromEnvDefaults verifies defaults are used when env vars are absent or empty.
+func TestConfigFromEnvDefaults(t *testing.T) {
+	t.Setenv("TRACING_ENABLED", "")
+	t.Setenv("TRACING_SERVICE_NAME", "")
+	t.Setenv("TRACING_SERVICE_VERSION", "")
+	t.Setenv("TRACING_ENVIRONMENT", "")
+	t.Setenv("TRACING_OTLP_ENDPOINT", "")
+	t.Setenv("TRACING_JAEGER_ENDPOINT", "")
+	t.Setenv("TRACING_SAMPLE_RATE", "")
+
+	cfg := ConfigFromEnv()
+	def := DefaultConfig()
+
+	require.Equal(t, def, cfg)
+}
+
+// TestConfigFromEnvOverrides verifies valid env vars override defaults.
+func TestConfigFromEnvOverrides(t *testing.T) {
+	t.Setenv("TRACING_ENABLED", "true")
+	t.Setenv("TRACING_SERVICE_NAME", "gateway")
+	t.Setenv("TRACING_SERVICE_VERSION", "1.2.3")
+	t.Setenv("TRACING_ENVIRONMENT", "production")
+	t.Setenv("TRACING_OTLP_ENDPOINT", "https://otel-collector:4318/v1/traces")
+	t.Setenv("TRACING_JAEGER_ENDPOINT", "http://jaeger:14268/api/traces")
+	t.Setenv("TRACING_SAMPLE_RATE", "0.25")
+
+	cfg := ConfigFromEnv()
+	require.True(t, cfg.Enabled)
+	require.Equal(t, "gateway", cfg.ServiceName)
+	require.Equal(t, "1.2.3", cfg.ServiceVersion)
+	require.Equal(t, "production", cfg.Environment)
+	require.Equal(t, "https://otel-collector:4318/v1/traces", cfg.OTLPEndpoint)
+	require.Equal(t, "http://jaeger:14268/api/traces", cfg.JaegerEndpoint)
+	require.Equal(t, 0.25, cfg.SampleRate)
+}
+
+// TestConfigFromEnvInvalidSampleRate verifies invalid sample rate falls back to default.
+func TestConfigFromEnvInvalidSampleRate(t *testing.T) {
+	t.Setenv("TRACING_SAMPLE_RATE", "not-a-float")
+
+	cfg := ConfigFromEnv()
+	require.Equal(t, DefaultConfig().SampleRate, cfg.SampleRate)
+}
+
+// TestConfigFromEnvLegacyEndpointFallback verifies legacy env var is used when OTLP endpoint is unset.
+func TestConfigFromEnvLegacyEndpointFallback(t *testing.T) {
+	t.Setenv("TRACING_OTLP_ENDPOINT", "")
+	t.Setenv("TRACING_JAEGER_ENDPOINT", "http://legacy:14268/api/traces")
+
+	cfg := ConfigFromEnv()
+	require.Equal(t, "http://legacy:14268/api/traces", cfg.OTLPEndpoint)
+	require.Equal(t, "http://legacy:14268/api/traces", cfg.JaegerEndpoint)
+}
+
+// TestConfigFromEnvEndpointPrecedence verifies OTLP endpoint has precedence over legacy Jaeger endpoint.
+func TestConfigFromEnvEndpointPrecedence(t *testing.T) {
+	t.Setenv("TRACING_OTLP_ENDPOINT", "https://collector:4318/v1/traces")
+	t.Setenv("TRACING_JAEGER_ENDPOINT", "http://legacy:14268/api/traces")
+
+	cfg := ConfigFromEnv()
+	require.Equal(t, "https://collector:4318/v1/traces", cfg.OTLPEndpoint)
+	require.Equal(t, "http://legacy:14268/api/traces", cfg.JaegerEndpoint)
+}