Senior Full Stack Engineer (JavaScript, Payments, Scalable Systems)
Senior Full Stack Engineer (JavaScript, Payments, Scalable Systems)

Senior Full Stack Engineer (JavaScript, Payments, Scalable Systems)

Kingston upon Thames Full-Time 28800 - 48000 £ / year (est.) No home office possible
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At a Glance

  • Tasks: Build and scale secure payment systems while designing full-stack features.
  • Company: Join EQUALS TRUE, a remote-first company committed to inclusivity and fair pay.
  • Benefits: Enjoy flexible salary options, paid holidays, wellness benefits, and free language classes.
  • Why this job: Be part of a mission-driven team that values diversity and social impact in tech.
  • Qualifications: Proven experience in full-stack JS applications and API integration, especially in fintech.
  • Other info: Open to all qualified candidates, with a strong commitment to equality and inclusion.

The predicted salary is between 28800 - 48000 £ per year.

REMOTE FIRST, AND INCLUSIVE ALWAYS. EQUALS (=) TRUE started when a type design geek and a talent nerd decided to create real change in the technology industry workforce. We are the only organization in Latin America that was founded with a commitment to be inclusive, treat individuals fairly, pay them equally, and provide them with a great professional experience each day. These values are what grounds our business model and practices each day.

Here’s what you need to know about this position:

THE WORK
  • Build and scale robust payment agents that handle sensitive financial and health data securely.
  • Design and ship full-stack features across patient flows, provider dashboards, and internal tools.
  • Take ownership of architecture and implementation from concept to production.
  • Collaborate directly with the founder and early users to refine UX and business logic in real time.
  • Integrate complex APIs like Plaid, Finix, and Stripe to enable seamless transactions.
  • Set up foundational engineering practices, deployment pipelines, and compliance workflows.
  • Contribute to a thoughtful, product-minded engineering culture as one of the early builders.
NEEDED EXPERTISE
  • Proven experience building and scaling full-stack JS applications with intuitive UX and well-structured business logic.
  • Comfortable thriving in fast-paced, early-stage startup environments with high ambiguity and high bias for disruption.
  • Demonstrated ability to independently own and deliver production-ready features from start to finish.
  • Product-minded approach with a keen eye for usability, performance, and real-world impact.
  • Hands-on experience integrating third-party APIs, especially in payments and fintech domains.
  • Bonus points for experience with HIPAA-compliant systems, healthcare technology, or RPA tools.
  • Strong history of establishing/working with standards such as peer review, peer coding, clear documentation, 80%+ code coverage automated testing, and more.
OUR BENEFITS & PERKS
  • We pay in USD on a platform that allows you to convert, allocate and disburse your salary as you want and into almost any currency that you choose.
  • Paid Company Holidays.
  • Medical, Safety, & Wellness benefits.
  • Free live business language classes.
  • Being part of an organization with a strong social mission for inclusion, fairness, and belonging.
  • …and more perks being added all the time.

Interested? Great! Please send us your CV/Resume to start the conversation and learn more about each other.

EQUALS TRUE is a global inclusive talent network of like-minded software engineers, agileist, and design thinkers. We build and develop safe, inclusive, equitable and balanced teams for companies that need to scale globally in a socially responsible way. EQUALS TRUE is open to all qualified candidates. We never evaluate qualified people on anything other than their skills, work history, training, and ability to do the job. We respect the right of people to live the life they want without judgements. So we practice wage equality, create a culture of belonging, insist upon respect for all our people, make every effort to accommodate all disabilities, and work only with companies that share our values. We are proud to be a global equal opportunity employer. And as such we never discriminate based on race, religion, color, national origin, disability, sexual orientation, gender, gender identity, status as a veteran, or any other protected status. We also consider qualified applicants with non-violent and non-financial related criminal histories. Additionally, EQUALS TRUE is committed to providing reasonable accommodations for candidates with disabilities throughout our hiring processes. If you need any assistance or accommodations due to a disability, please let us know.

Senior Full Stack Engineer (JavaScript, Payments, Scalable Systems) employer: equalstrue

EQUALS TRUE is an exceptional employer that champions inclusivity and fairness in the tech industry, offering a remote-first work culture that prioritises employee well-being and professional growth. With competitive benefits such as paid company holidays, medical and wellness support, and opportunities for continuous learning, we empower our team to thrive while making a meaningful impact in the world of technology. Join us as we build a diverse and equitable workforce, where your skills and contributions are valued and celebrated.
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Contact Detail:

equalstrue Recruiting Team

StudySmarter Expert Advice 🤫

We think this is how you could land Senior Full Stack Engineer (JavaScript, Payments, Scalable Systems)

✨Tip Number 1

Familiarise yourself with the specific technologies mentioned in the job description, such as JavaScript and payment APIs like Plaid, Finix, and Stripe. Having hands-on experience or projects that showcase your skills in these areas will make you stand out.

✨Tip Number 2

Demonstrate your ability to work in fast-paced environments by sharing examples of past projects where you successfully navigated ambiguity and delivered results. This will show that you can thrive in a startup culture.

✨Tip Number 3

Highlight any experience you have with HIPAA-compliant systems or healthcare technology, as this is a bonus point for the role. If you don’t have direct experience, consider discussing related projects that required strict compliance or security measures.

✨Tip Number 4

Engage with the company's social mission by researching their values and preparing to discuss how your personal beliefs align with theirs. Showing that you resonate with their commitment to inclusion and fairness can set you apart from other candidates.

We think you need these skills to ace Senior Full Stack Engineer (JavaScript, Payments, Scalable Systems)

Full Stack JavaScript Development
Payment Systems Integration
API Integration (Plaid, Finix, Stripe)
UX Design and Usability
Scalable System Architecture
Production-Ready Feature Delivery
Compliance with HIPAA Standards
Automated Testing and Code Coverage
Agile Methodologies
Documentation and Code Review Practices
Problem-Solving in High Ambiguity Environments
Collaboration with Cross-Functional Teams
Performance Optimisation
Product-Minded Approach

Some tips for your application 🫡

Tailor Your CV: Make sure your CV highlights your experience with full-stack JavaScript applications, especially in payments and fintech. Emphasise any relevant projects that showcase your ability to build and scale robust systems.

Craft a Compelling Cover Letter: Write a cover letter that reflects your understanding of the company's mission and values. Discuss how your skills align with their needs, particularly in creating intuitive UX and integrating complex APIs.

Showcase Relevant Experience: In your application, provide specific examples of past projects where you took ownership from concept to production. Highlight your experience in fast-paced environments and your product-minded approach.

Highlight Cultural Fit: Since the company values inclusivity and fairness, mention any experiences or initiatives you've been part of that demonstrate your commitment to these principles. This will help show that you align with their culture.

How to prepare for a job interview at equalstrue

✨Showcase Your Full-Stack Experience

Be prepared to discuss your previous projects involving full-stack JavaScript applications. Highlight specific examples where you designed and implemented features, focusing on your role in the architecture and how you ensured a great user experience.

✨Demonstrate Your API Integration Skills

Since the role involves integrating complex APIs like Plaid, Finix, and Stripe, come ready to talk about your experience with these or similar APIs. Share any challenges you faced and how you overcame them to ensure seamless transactions.

✨Emphasise Your Product-Minded Approach

Discuss how you prioritise usability and performance in your work. Be ready to provide examples of how your decisions have positively impacted the end-user experience and contributed to the overall success of a project.

✨Prepare for Cultural Fit Questions

Given the company's strong social mission and commitment to inclusion, think about how your values align with theirs. Be ready to share your thoughts on creating an inclusive workplace and how you've contributed to a positive team culture in the past.

Senior Full Stack Engineer (JavaScript, Payments, Scalable Systems)
equalstrue
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  • Senior Full Stack Engineer (JavaScript, Payments, Scalable Systems)

    Kingston upon Thames
    Full-Time
    28800 - 48000 £ / year (est.)

    Application deadline: 2027-07-11

  • E

    equalstrue

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