Mid/Senior Full-Stack Developer - Long Term

About us
We’re building a data platform. Our product is deeply data-driven, with a strong focus on performance, reliability, and long-term maintainability.

We are actively looking for a Full-Stack Developer (Next.js/TypeScript, backend-heavy, 3+ years of experience) to join us on a long-term basis and help strengthen and scale our backend and platform as we grow.

We are a fully remote team, with team members based in Europe and South Africa, and we value autonomy, ownership, and clear communication.

Role Description
This is a remote freelance contract role for a full-stack developer with a strong backend focus. You will be responsible for designing, hardening, and maintaining efficient and reliable server-side applications and systems, as well as working within our Next.js app where needed.

You will:
→ Add test coverage + CI/CD pipeline
→ Fix database issues (race conditions, connection pooling, query optimization)
→ Implement performance fixes (pagination, caching)
→ Review architecture for scale
→ Set up monitoring & structured logging
→ Secure & optimize API routes (validation, rate limiting, error handling)
→ Improve background jobs & webhooks reliability (Inngest)
→ Harden authentication & authorization flows (Clerk + Next.js middleware, RBAC, secure sessions)
→ Optimize Supabase/PostgreSQL & ClickHouse queries and data model for high-volume data (Billions of raws)
→ Ensure secure, robust usage of Next.js 15 Server Actions & API routes

Tech Stack
- Next.js 15 (API Routes, Server Actions, React)
- PostgreSQL + Supabase + ClickHouse
- Vercel, Inngest, Clerk
- TypeScript

Must have
- 4–5+ years Node.js/TypeScript backend experience
- 2–3+ years building production systems with Next.js
- Strong PostgreSQL experience (transactions, performance, indexing, connection pooling)
- REST API design & security (auth, input validation, rate limiting)
- Testing (unit + integration) and CI setup experience
- Database architecture & schema design
- Experience stabilizing and refactoring existing codebases, not just greenfield
- Comfortable working across backend and the Next.js app layer

Nice to have
- Experience with Clerk or similar auth providers
- Experience with Supabase
- Experience with ClickHouse or other OLAP databases
- Experience with Vercel and serverless deployments
- Experience with background jobs & webhooks orchestration (Inngest or similar)
- Previous work on data-heavy SaaS or analytics platforms

Budget: $1,000–$2,000/month
Type: Long-term freelance (no agencies)
Availability: Full-time
Start: ASAP
Location: Europe / South Africa
NO AGENCY