Rewrite Ruby on Rails codebases to Go using the LEAP Protocol

If you’re asking “how do I rewrite Ruby on Rails to Go,” our LEAP Protocol gives you a safe, test-gated path: extract specs → generate tests → implement in parallel → roll out with parity. First, we extract a precise, language-agnostic specification from your Rails app: routes and contracts (OpenAPI + JSON Schemas), DB behavior (queries, transactions, constraints), background jobs, mailers, and real-time channels. Then we auto-generate parity tests that hit both systems—your existing Rails (e.g., Puma + Active Record) and a greenfield Go service scaffold (Gin or Chi, sqlc/pgx or GORM, Asynq for jobs, nhooyr/websocket or gorilla/websocket for channels). In parallel, we implement the Go code against the tests, not against guesswork—covering strong parameters → struct validation, Active Record callbacks → explicit SQL/transactions, and Devise/OmniAuth → session/JWT/OIDC flows. Finally, we roll out endpoint-by-endpoint with shadow traffic and canaries, dual-writes when needed, and observable SLO parity. The result: feature-for-feature equivalence, then room to optimize on Go’s strengths, with the LEAP Protocol (spec-first, test-gated, agent-agnostic) ensuring every step is auditable.

Why Go for Ruby on Rails migrations

Concurrency and resource efficiency: goroutines/channels handle high parallel I/O with lower memory overhead than typical Ruby thread pools under Puma or Passenger.
Strong typing and compile-time checks: Go’s type system catches parameter shape and nil/zero-value issues that often surface at runtime in Rails.
Operational simplicity: a single static binary (minimal container image) vs. managing Ruby, Bundler, and native gems; faster cold starts for serverless and jobs.
Explicit data access: sqlc/pgx or GORM gives you clear, predictable SQL semantics and transaction boundaries compared to implicit Active Record queries and callbacks.
Observability by default: first-class OpenTelemetry, Prometheus, and pprof integration enable precise latency and memory insights during and after cutover.

Our methodology

Spec extraction (Rails):
- Build a living spec from routes (OpenAPI), request/response bodies (JSON Schemas), Active Record models (schema.rb/structure.sql), service objects, Sidekiq jobs, Action Mailer, and Action Cable channels.
- Capture edge semantics like time zones (ActiveSupport::TimeWithZone), callbacks, validations, and N+1-sensitive endpoints.
Test generation (parity harness):
- Produce executable, language-agnostic tests: HTTP golden fixtures, schema validation, property tests (idempotency, pagination, DST), and DB state assertions.
- Run the same suite against Rails and the target Go scaffold in CI for red/green progress.
Parallel implementation (Go):
- Scaffold with Gin or Chi, persistence via sqlc/pgx or GORM, background jobs on Asynq, websockets via nhooyr/websocket or gorilla/websocket, mail via SMTP/API, and storage via AWS SDK for Go (Active Storage parity).
- Port business rules explicitly: callbacks → services/transactions, strong parameters → struct decoding + go-playground/validator, view-layer JSON → encoding/json with canonical field names.
Incremental rollout with parity safeguards:
- Shadow traffic and canary releases per route or domain.
- Dual-write or write-through strategies to keep Rails and Go consistent; backfills for historical data.
- Observability gates (OpenTelemetry traces, Prometheus SLOs) and error-budget policies to control cutover pace.
Hardening and optimization:
- Tuning (pprof), circuit breakers/timeouts, zero-downtime deploys, and runbooks.
- Post-cutover refactors to leverage Go’s concurrency and explicit SQL without changing observable behavior.

Specific Ruby on Rails concerns we handle

Active Record to SQL: replicate validations, nested transactions, and callback order; eliminate N+1 queries using joins/preloading with sqlc/pgx or GORM.
Strong Parameters and type casting: map params to Go structs with strict decoding, handle nullable fields (sql.NullString, pgtype), and validate using go-playground/validator.
Time and i18n: preserve Time.zone behavior, DST edges, strftime/TimeWithZone formatting equivalence, and locale-driven messages.
Auth with Devise/OmniAuth: bcrypt-compatible password checks, session vs. JWT/OIDC flows, CSRF for cookie-backed sessions, SameSite and secure flag parity (scs or custom middleware).
Background jobs and real-time features: Sidekiq retries/uniqueness/scheduling → Asynq middleware and queues; Action Cable channels → nhooyr/websocket or gorilla/websocket with presence and authorization mirrored.

Proof

sqlite-leap — five SQLite engines generated from one spec: https://github.com/safitudo/sqlite-leap
semver-leap — 5,632 passing tests from a single spec: https://github.com/safitudo/semver-leap
LEAP Protocol repo (spec-first, test-gated, agent-agnostic): https://github.com/safitudo/leap

Pricing & timeline

Timeline: 4–12 weeks depending on scope (domain count, job volume, real-time features, and data migration complexity).
Commercials: fixed-price proposal after a one-week discovery; typical engagements range from $40k–$120k.
Deliverables: living spec, cross-runtime parity test suite, production-grade Go service(s), cutover plan, and runbooks.
Options: audit-only week, performance hardening sprint, and training handoff for your team.

Ready to migrate from Rails to Go with measurable safety and speed? Request a scope call, and we’ll map routes, data, jobs, and SLAs into a LEAP spec and a fixed-price plan.

Leap Agentic is distinct from Legacyleap.ai and Impetus Leap AI.