Full Stack Engineer

Overview Strong data integrity. APIs: REST, OAuth 2.0, JSON schemas, Postman. Database: PostgreSQL.

Through proprietary software and AI, Sleek makes the back-office easy for micro SMEs. We give Entrepreneurs time back to focus on what they love doing - growing their business and being with customers. With a surging number of Entrepreneurs globally, we are innovating in a highly lucrative space. We operate 3 business segments:

Corporate Secretary: Automating the company incorporation, secretarial, filing, Nominee Director, mailroom and immigration processes via custom online robots and SleekSign. We are the market leaders in Singapore with :5% market share of all new business incorporations

Accounting & Bookkeeping: Redefining what it means to do Accounting, Bookkeeping, Tax and Payroll thanks to our proprietary SleekBooks ledger, AI tools and exceptional customer service

FinTech payments: Overcoming a key challenge for Entrepreneurs by offering digital banking services to new businesses

Sleek launched in 2017 and now has around 15,000 customers across our offices in Singapore, Hong Kong, Australia and the UK. We have around 500 staff with an intact startup mindset.

We have recently raised Series B financing off the back of >70% compound annual growth in Revenue over the last 5 years. Sleek has been recognised by The Financial Times, The Straits Times, Forbes and LinkedIn as one of the fastest growing companies in Asia.

Backed by world-class investors, we are on track to be one of the few cash flow positive, tech-enabled unicorns based out of Asia Pacific.

Role The Full-Stack Product Engineer

is responsible for owning the architecture, development, and scaling of Sleek's next-generation digital products.

Mission This role's mission

is to combine backend engineering, API integration, and frontend development to deliver secure, performant, and user-centric web applications that integrate seamlessly with Sleek's CRM and analytics systems.

You'll work closely with product, design, and growth teams to take products from prototype → launch → global scale, ensuring:

High engineering quality

Full security and compliance

Strong data integrity

Smooth user experience

Outcomes Build and Launch the MTD Product Backend

Develop the core backend system for the Making Tax Digital (MTD) product — including sandbox and live HMRC integrations

Ensure the product meets production-grade reliability, security, and compliance standards

Deliver clear API documentation and support multi-environment deployments (sandbox → live)

Integrate Sleek's CRM and Analytics Systems

Connect the product's backend with Sleek's CRM for customer and transaction data flow

Implement event tracking and analytics integrations (e.g. Mixpanel, GA4, PostHog) for real-time product insights

Define and deploy conversion and engagement metrics pipelines to enable data-driven growth

Deploy to Scalable Production Infrastructure

Lead the end-to-end deployment of the full-stack system using AWS, Railway, or Vercel

Set up CI/CD pipelines and monitoring for uptime, error tracking, and security compliance

Achieve production reliability and cost-optimized serverless scaling

Deliver a Secure, Compliant Platform

Implement GDPR-compliant data handling and secure OAuth 2.0 flows for authentication and integrations

Establish and document best practices for encryption, API security, and access control

Enable Long-Term Maintainability

Produce clean, testable, and documented codebases using FastAPI / Node.js / React / Next.js

Set up unit/integration testing frameworks (Pytest, Jest, Postman suite)

Ensure future engineers can easily extend and scale the system

Requirements

6-8 years overall, with 2+ years building production B2B SaaS or FinTech products

Backend: Node.js / Nest.js

Frontend: React / Next.js

APIs: REST, OAuth 2.0, JSON schemas, Postman

DevOps: AWS, Docker, CI/CD pipelines

Security: GDPR

Database: PostgreSQL

Proven record of delivering live, production-grade systems independently or as lead developer

Experience taking prototypes to production (Replit to AWS/Vercel)

Experience in working in a fast paced environment of a startup

Strong grasp of scalable architecture and complex API integrations

Confident in making technical decisions in fast-paced environments

Bonus: experience with accounting, tax, or FinTech APIs

Behavioural fit

Ownership: This shows reliability and helps build trust within the team. We move fast and need to know that everyone will see things through to completion and proactively help to get things back on track when challenges arise. Accountability is really important to us.

Humility: There is so much we don't know. Humility allows for open-mindedness to feedback and a willingness to learn from others. It paves the way for collaboration and creates a positive work environment. It is a key ingredient of self awareness and emotional intelligence.

Structured Thinking: Our business is complex with many layers (many services, many countries, many cultures). Regardless of whether you're more analytical or creative in nature, being able to show sound judgement is important to us. It ensures solutions are pragmatic and balance the needs of the organisation, team and customers.

Attention to detail: You'll be managing multiple, complex workstreams from numerous stakeholders. It will be important for you to keep track of everything and notice when information is missing or inconsistent.

Excellent listener and clear communicator: We have a variety of nationalities and for many people, English isn't their first language. For you to excel, you'll need to be present in your calls and make sure you properly receive and thoughtfully send messages to others in the business.

Analytical Mindset: You have a keen eye for detail and a methodical approach to dissecting problems. You excel at analysing complex systems and processes to identify weaknesses and inefficiencies, and your ability to evaluate multiple scenarios enables you to devise the best testing strategies. You apply data-driven decisions to enhance testing coverage and performance metrics, ensuring the highest standards of software quality.

Collaboration-Driven: You thrive in a cross-functional team environment, working closely with developers, product managers, and operations teams to ensure alignment on requirements and testing goals. You communicate effectively, advocate for quality throughout the development process, and proactively address potential issues before they arise, fostering a culture of shared responsibility for delivering exceptional software.

Data driven: We are a data rich business with :15,000 small customers. Each decision we make can impact many more people than we realise - so it's critical that we use sound data to support our strategies and review the success of our initiatives.

Can have tough conversations in a positive way: It's not a matter of if, but when difficult interpersonal situations arise. Disagreement, conflict and disappointment are a given in a fast moving business where people care about their work. People that proactively have tough conversations with kindness build empathy, trust and great working relationships.

Interview Process

The successful candidate will participate in the below interview stages.

TA Screening: A 30 minute chat with a member of the HR Team

Technical Interview: A 90 minute chat with a member of the team to validate the technical expertise of the candidate.

Hiring Manager Interview: A 90 minute chat with the Hiring Manager to validate the technical aptitude of the candidate.

Soft Skills/Behavioral Fit Interview: A 30-45 minute chat with the leadership to validate our desired experience.

Offer + reference calls: We'll make a non-binding offer verbally or over email, followed by a couple of short phone or video calls with references that you provide to us.

Background checks Requirement for background screening: Sleek is a regulated entity and as such is required to perform different levels of background checks on staff depending on their role. This may include using external vendors to verify the below: your education, any criminal history, any political exposure, any bankruptcy or adverse credit history. We will ask for your consent before conducting these checks. Depending on your role at Sleek, an adverse result on one of these checks may prohibit you from passing probation.

Legal acknowledgement By submitting a job application, you confirm that you have read and agree to our Data Privacy Statement for Candidates, found at sleek.com.

Benefits

Humility and kindness: Humility is a core attribute we hire for, which means we have a culture of not taking ourselves too seriously and being able to laugh. Kindness is also incredibly important. We are committed to creating and nurturing a diverse and inclusive environment.

Flexibility: You'll be able to work from home. If you need to start early or start late to cater to your family or other needs, we don't mind, so long as you get your work done and proactively communicate.

Financial benefits: We pay competitive market salaries and provide staff with generous paid time off and holiday schedules. Additionally, you'll be able to access our flexi benefits scheme for home office equipment or health and fitness expenditure. Certain staff at Sleek are also eligible for ...