Senior Full-Stack Engineer, Typescript

UserEvidence

Senior Full-Stack Engineer at UserEvidence working on a customer advocacy SaaS platform. Stabilizing and evolving product through re-architecture, feature work, and bug triage.

Posted 6/2/2026full-timeRemote • 🇧🇷 BrazilSeniorWebsite

Tech Stack

Tools & technologies

JavaScriptNext.jsNode.jsPostgresReactSQLTypeScript

About the role

Key responsibilities & impact

You'll be part of a senior engineering team responsible for stabilizing and evolving UE Advocacy. Depending on focus area, you may work in one of three lanes:
- **Re-architecture.** Port modules from the legacy Express API to the new Hono API with full integration test coverage. Decompose large React components (3,000-5,000 LOC pages) and convert .jsx to strict-mode .tsx. Improve frontend performance — bundle splitting, dynamic imports, mobile-first defensive coding, embed reliability. Harden data integrity by introducing real state machines and typed enums.
- **Feature work.** Build new customer-facing features behind feature flags with canary rollouts, against PM-written acceptance criteria. Follow established backend patterns and frontend conventions exactly — we have reference modules for a reason.
- **Bug triage and fixes.** Investigate customer-reported bugs using New Relic traces, structured logs, and database queries. Reproduce, fix, and add tests to prevent regression. Most bugs live in legacy code; finding them is a code-archaeology skill.
Across all three lanes, you will:
Write clean, maintainable, well-tested code following established patterns
Conduct thoughtful peer code reviews and respond constructively to the same
Use automated code review (Macroscope), automated tests (Bun, Vitest, Playwright), and canary deploys as your safety net — not manual full-app QA
Troubleshoot production issues using New Relic, structured logs, and direct database queries

Requirements

What you’ll need

At least six years building software in a team environment, or equivalent demonstrable experience. Years of experience don't always capture expertise — apply if you can show your work.
At least four years working professionally with TypeScript, including in strict mode. Experience refactoring weakly-typed code to strict TypeScript is a strong plus.
Production experience with at least one modern Node/Bun backend framework (Hono, Fastify, Express, Koa, or similar).
Production experience with a typed ORM (Prisma strongly preferred; Drizzle, TypeORM, or similar are acceptable).
Production experience writing complex SQL queries against PostgreSQL.
Production experience with a background job system (BullMQ, Sidekiq, Celery, SQS-backed workers, or similar).
Production experience with React. Next.js experience is a strong plus.
Production experience writing integration tests against a real database. You understand why mocking the ORM is the wrong default.
Comfortable working in a codebase under active rewrite, where the answer to "how should I do this?" is "go read the canonical reference module and match its pattern."
Comfortable working remotely in an autonomous environment — you don't mind asking questions and problem-solving in public communication channels.
Able to collaborate during US time zones — you don't have to live in them, but you have to overlap.
You must be located in South or Central America. We are not currently accepting US-based or Europe-based applicants.
AI-forward — required, not optionalThis is a non-negotiable for this role. We treat AI agents as primary force multipliers in daily engineering work, and we expect every engineer here to operate the same way. We aren't looking for AI-curious; we're looking for AI-fluent.
What that means concretely:
You drive agents to do substantive work, not just autocomplete. Claude Code, Cursor, Codex, or similar — your tool of choice. You can decompose a task, give the agent the right context, review what it produces critically, and iterate.
You have shipped real production code substantially authored by an agent. You can talk about a specific recent example: what worked, what failed, where you had to push back.
You treat agent output like a junior engineer's PR. You verify behavior, you write the tests, you read every line before committing. You never commit code you don't understand.
You know when not to use an agent — when prompting takes longer than typing, when the problem needs intuition the agent doesn't have, when correctness needs hand-verification.
You produce the artifacts that make agents more effective: clear specifications, well-shaped tasks, reference modules, skill definitions, review checklists. You understand that good context-engineering is the new senior-engineer skill.
You're comfortable in agent-driven workflows — spec-then-implement, parallel subagents, plan-then-execute, TDD with an agent pair.

Benefits

Comp & perks

Competitive salary and bonus + a large equity stake. We pay in the 75th percentile of market rates.
Unlimited PTO + 13 paid holidays per year.
$4,000 equipment allowance for your first two years, $3,000 budget every following two years.
Health, dental, vision insurance.
Individual learning + development budget (up to $2,500/year).
Flexible work schedule and remote work options.
Coworking space membership reimbursement.

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Hard Skills & Tools

TypeScriptNode.jsReactNext.jsSQLPostgreSQLPrismaBunHono APIintegration testing

Soft Skills

collaborationproblem-solvingpeer code reviewscommunicationautonomycritical thinkingcontext-engineering