Eterstain

We are working on a Database / B2B SaaS and looking for an experienced backend developer to join our team

  YOUR MISSION:
  → 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
  → Background jobs & webhooks reliability (Inngest)

  TECH STACK:
  • Next.js 15 (API Routes, Server Actions)
  • PostgreSQL + ClickHouse
  • Vercel, Inngest, Clerk

MUST HAVE:
  • 5+ years Node.js/TypeScript backend
  • PostgreSQL (transactions, performance)
  • REST API design & security
  • Testing
  • Database architecture & schema design
  • Experience stabilizing existing codebases, not just greenfield

  Budget: $1,000-$2,000/month
  Type: Full-time
  Start: ASAP
  Opportunity: Long-term
  NO AGENCY

About us

We are a data-first platform building reliable, scalable infrastructure around complex data workflows. Our product is deeply data-driven, with a strong focus on performance, reliability, and long-term maintainability.

We are actively looking for a Backend Developer (mid–senior level, 3+ years of experience) to join us on a long-term basis and help strengthen and scale our backend systems 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 Backend Developer. The Backend Developer will be responsible for designing, building, and maintaining efficient and reliable server-side applications and systems. The role involves developing APIs, ensuring system scalability, debugging applications, and collaborating with front-end developers to create seamless workflows. You will work independently while maintaining clear and effective communication with the team.

Your mission:

 → 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

 → Background jobs & webhooks reliability (Inngest)

Tech Stack:

 • Next.js 15 (API Routes, Server Actions)

 • PostgreSQL + ClickHouse

 • Vercel, Inngest, Clerk

Must have:

 • 5+ years Node.js/TypeScript backend

 • PostgreSQL (transactions, performance)

 • REST API design & security

 • Testing

 • Database architecture & schema design

 • Experience stabilizing existing codebases, not just greenfield

 Budget: $1,000-$2,000/month

 Type: Full-time

 Start: ASAP

 Opportunity: Long-term

 NO AGENCY

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

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

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–$3,000/month
Type: Long-term freelance (no agencies)
Availability: Full-time
Start: ASAP
Location: Europe / South Africa
 

About Us

We're building a B2B sales intelligence platform for international trade. Our software helps companies discover new buyers and suppliers worldwide and connect with the right decision-makers.

Most businesses struggle to find reliable partners abroad. We're making global trade accessible to everyone, not just large corporations with dedicated export sales / procurement teams.

We're a young and growing company with active clients using our platform daily. Our team is lean, 2 founders, a strong team of advisors, a lead developer, and we're looking for a full-stack developer and other roles to join us and help build the next biggest trade market intelligence platform in the world.

Role Description

We're looking for a freelance full-stack developer with a strong backend focus. You'll ship new features, solve real problems, and help shape the technical foundations of a product that's growing.

Today, one the founder handles the product and works with one technical lead. You'd be the second person on the tech side, a structuring role with real impact and direct input on key decisions.

You'll have full ownership of your work, from idea to production. That means making technical decisions yourself, validating your own features, and shipping with confidence. You won't be alone, you'll work closely with the technical lead and get support on architecture and complex decisions. But you'll still own your deliverables.

You will:

• Debug and resolve production issues (performance bottlenecks, race conditions, data inconsistencies)
• Add test coverage + CI/CD pipeline
• Implement performance fixes (pagination, caching)
• Set up monitoring
• 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 rows)
• Ensure secure, robust usage of Next.js 15 Server Actions & API routes

Team & Working Environment

You'll join a very small team with few formal processes and a product that's still early-stage. This means strong autonomy and individual responsibility. You'll own problems end-to-end, make technical trade-offs on your own, and validate your work before shipping.

Day-to-day, you'll be working on a product that's already in production, used by real clients. That means debugging real incidents, making technical trade-offs without detailed specs, and iterating fast: ship, observe, improve. We have two daily syncs, one in the morning to align, one at end of day to review progress

Tech Stack

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

Must Have

• 2+ years Node.js/TypeScript backend experience
• 2+ years building production systems with Next.js
• Strong PostgreSQL experience (transactions, performance, indexing, connection pooling)
• REST API design & security (auth, input validation, rate limiting)
• Experience stabilizing and refactoring existing codebases, not just greenfield
• Comfortable working across backend and the Next.js app layer

What are you looking for in a hire?

• Curious & Growth-Oriented: You stay up to date with new tools and frameworks, and actively seek opportunities to expand your skills
• Resourceful Problem-Solver: You take initiative when facing blockers and find solutions independently
• Strong Ownership Mindset: You care deeply about the end-user experience and aren't afraid to challenge decisions to improve the product
• Execution-Focused: You prioritize shipping and iterating over perfection
• Proactive Communicator: You keep the team informed, articulate ideas clearly, and ask for help when needed

Why Working With Us?

• Real impact from day one: your code ships to production and is used by real clients immediately
• Learn fast: work directly with the founders on a product that's growing and evolving rapidly
• Ownership: you won't execute tickets, you'll own problems and solve them
• Early-stage opportunity: join at 6 months in, grow with the company as we scale
• Autonomy: you're trusted to make decisions and work independently, with guidance on priorities and people around to help when needed

• Contract: Freelance, with opportunity to convert to CDI (Contrat à Durée Indéterminée)
• Compensation: €2,500–3,500/month
• Location: On-site in Paris preferred, open to full remote for other European locations
• Engagement: Full-time