Freelance Backend Engineer

Foxtek; Amsterdam; Hybrid; EUR 96,000 - 179,000; Full time

Benefits offered by this job

Hybrid working

Competitive freelance rates

Job summary

Foxtek in Amsterdam is seeking an experienced freelance Senior Backend Engineer to own design and development of scalable, cloud-native backend systems. The role is ~90% backend, ~10% frontend, with a hybrid arrangement (1 day onsite per week) and a 12-month contract.

You will design and implement backend services in TypeScript/Node.js, build serverless AWS solutions, and work with DynamoDB and REST APIs. Collaboration with engineers and stakeholders is essential.

Qualifications

• Strong commercial experience with TypeScript and Node.js.
• Hands-on production AWS Serverless experience (Lambda).
• Experience with SNS, SQS and EventBridge.
• Knowledge of DynamoDB including single-table design.
• Experience designing REST APIs and event-driven systems.
• Understanding of system design, async processing, caching, and distributed architectures.
• Ability to explain technical decisions and trade-offs.

Responsibilities

• Design, develop and maintain scalable backend services using TypeScript/Node.js.
• Build serverless, event-driven apps on AWS.
• Design APIs, integrations and complex workflows.
• Model DynamoDB data and access patterns.
• Make architectural decisions for scalability and reliability.
• Own solutions from design to production and collaborate with stakeholders.

Skills

TypeScript

Node.js

AWS Serverless

REST APIs

System design

Distributed architectures

Asynchronous processing

Caching

Decision explanations

Tools

SNS

SQS

EventBridge

DynamoDB

Terraform

AWS CDK

React

Python

Job description

Location: Amsterdam, Netherlands (Hybrid - 1 day onsite per week)

Contract: 12 months

Hours: 35 billable hours per week

Rate: Competitive, dependent on experience

Start: ASAP

The Opportunity

We're working directly with an established, bank-backed Dutch fintech that's transforming how businesses access finance.

They're looking for experienced Freelance Senior Backend Engineers to join their engineering team, taking ownership of the design and development of scalable, cloud-native backend systems.

This is a genuinely hands-on engineering opportunity, where you'll have input into architectural decisions and work directly with the people building the products.

The focus is approximately 90% backend and 10% frontend.

What You'll Be Doing

• Designing, developing and maintaining scalable backend services using TypeScript and Node.js.
• Building serverless, event-driven applications on AWS.
• Designing APIs, integrations and complex business workflows.
• Working with DynamoDB, including data modelling and access patterns.
• Making architectural decisions around scalability, reliability, performance and maintainability.
• Taking ownership of solutions from initial design through to production.
• Collaborating directly with engineers and business stakeholders.

What We're Looking For

• Strong commercial experience with TypeScript and Node.js.
• Hands-on production experience with AWS Serverless, particularly Lambda.
• Practical experience with SNS, SQS and EventBridge.
• Strong knowledge of DynamoDB, including single-table design and modelling relationships between entities.
• Experience designing and developing REST APIs, integrations and event-driven systems.
• Strong understanding of system design, asynchronous processing, caching and distributed architectures.
• Ability to explain technical decisions, trade-offs and personal contributions to previous projects.

Beneficial experience:

• React
• Terraform / AWS CDK
• Python
• Financial services or fintech environments

The Type of Engineer We're Looking For

We're particularly interested in engineers who have personally designed AND built meaningful backend systems at scale.

Someone who can take a business problem, understand the requirements, propose an appropriate architecture and implement the solution independently.

This isn't a purely architectural position, nor is it simply a ticket-driven development role. You'll need to be equally comfortable discussing system design and writing production-quality code.

Why Consider This Opportunity?

• 12-month freelance assignment with an established fintech.
• Work directly within the end client's engineering team.
• Genuine ownership of architecture and implementation.
• Modern TypeScript and AWS Serverless environment.
• Hybrid working with approximately one day per week in Amsterdam.
• Competitive freelance rates reflecting technical expertise.
• Potential for multiple freelance engineers to join.