Ship products without hiring a full dev team. Deliver client work without scrambling for contractors. Sprint after sprint, Slark Labs keeps your roadmap moving.
Small team. No handoffs. No surprises.
10+ long-term partnerships. Products used by thousands of end users.
Slark Labs is a US-registered dev agency with a team of 7 engineers, trusted by agencies and SaaS founders since 2019.
Built for teams that need delivery, not delays.
You know what needs to be built. You just do not have the team to build it yet. We ship MVPs, features, dashboards, and internal tools so you can keep moving without pausing to recruit, hire, and manage engineers.
You sold the project. Now you need a dev team that delivers like it is their reputation on the line, because it is yours. We work white-label behind your brand on client builds, overflow work, and ongoing support — with no drama and no client-facing surprises.
The technical capabilities behind every product we ship.
We build SaaS products, dashboards, portals, and customer-facing web applications from the ground up. That means frontend interfaces, backend systems, databases, authentication, and deployment — architected as a single coherent product, not stitched together from disconnected pieces. Clean, maintainable code with clear documentation so your team or future engineers can pick up where we leave off.
Need to validate an idea, unblock a stalled roadmap, or ship a feature your team does not have bandwidth for? We run focused sprints scoped to a specific outcome — whether that is a working MVP, a major feature release, a third-party integration, or an internal system your operations team has been waiting on. Fast execution with production-quality standards, not throwaway prototypes.
Your clients see your brand. We do the engineering. We partner with agencies as an invisible development team — handling implementation, feature builds, client revisions, and ongoing maintenance under your name. We adapt to your project management tools, your communication style, and your delivery cadence. No client-facing surprises. No gaps that make your team look understaffed.
We design and build the backend systems that hold products together — RESTful and GraphQL APIs, database architecture, authentication flows, job queues, caching layers, and third-party integrations. Whether you need a clean API for a new product, a reliable integration between internal tools, or a backend refactor that reduces technical debt, we build systems that are structured to scale and straightforward to maintain.
We turn designs into fast, accessible, production-ready interfaces. Our frontend work is built primarily in React and TypeScript — component-driven, responsive, and engineered for real-world usage. Whether you are handing us Figma files or need us to make frontend decisions collaboratively, we deliver interfaces that feel polished and perform under load.
Not every team needs a project. Some need a development partner they can count on month after month. Our retainers cover continuous feature delivery, bug fixes, performance optimization, infrastructure maintenance, and release support — with consistent velocity and no re-onboarding. Your roadmap keeps moving. Your team stays unblocked. Nothing stalls because a contractor disappeared.
We build, customize and maintain WordPress sites and HubSpot portals for agencies and their clients. From custom themes and plugins to HubSpot app development and CMS implementation — we handle the full scope so your team doesn't have to. Ideal for: agencies with WordPress or HubSpot clients needing reliable dev support.
01
We begin by getting to know you and your project, exploring your technical requirements, objectives, and preferences to ensure our work aligns with your vision.
02
Based on precise specifications developed with you, we draw up a documented list of tasks to be executed with a detailed schedule that keeps everyone aligned.
03
We collaborate closely with you on designing your digital experience, ensuring it reflects your brand and meets user needs effectively.
04
We rely on the latest technologies and best practices to build a scalable solution. Whatever your technical needs, we guarantee transparent and efficient development.
05
Before launching, we conduct thorough tests to evaluate performance, functionality, and compatibility across different devices and browsers.
06
We work closely with you to coordinate a smooth launch. Your solution is published on a reliable and robust platform that meets your specific requirements.
We build differently because we've been on both sides of agency work
You won't waste time decoding vague status reports. We provide clear updates in plain language about what's shipping, what's next, and where things stand. No jargon, no confusion – just honest progress reports you can actually use.
We ship complete, production-ready work – not halfway features that your team has to finish later. Your product deserves more than "we'll clean that up in the next phase." When we build it, it's built right the first time.
Sprint, project, or retainer – we adapt to how you need to work. No pressure to sign year-long contracts when you only need a focused sprint. We scale up or down based on your actual business needs, not our revenue targets.
Most dev shops vanish after launch day. We stay engaged for the entire product lifecycle – helping with fixes, improvements, releases, and whatever comes next. We're building a relationship, not just checking off deliverables.
Our code is clean, documented, and built for longevity – but we're not precious about it. We value solutions that work for your business over technical purity contests. Your success drives our decisions, not our GitHub portfolios.
Most teams choose between hiring full-time, paying premium contractor rates, or rolling the dice on cheap offshore work. Here's where Slark Labs fits.
In-house Hire
US Contractor
Cheap Offshore
Slark Labs
Real feedback from teams we've partnered with
Founders, agencies, and product teams across Europe, the US, and beyond — references available when clients allow.
Slark Labs has been our go-to white-label dev partner for over a year, delivering across multiple client sites including a campaign that helped our client raise nearly $1.2M at a single event. Fast, reliable, no drama - exactly what you need in an agency partner.
Slark Labs understood the brief immediately and delivered a precise solution within the quoted timeline. The fix affected hundreds of our clients who are now very happy. Exactly the kind of reliable dev partner an agency needs.
Slark Labs helped us hit a critical release deadline, shipping new features and fixes without drama. A reliable development partner you can trust to deliver when it matters.
Slark Labs handled our MarianaTek integrations with precision and professionalism. Communicative, thorough and great quality work - I wouldn't hesitate to work with them again.
Slark Labs are truly full-stack, excelling in both front-end and back-end development. Clear communication throughout, and when faced with difficult challenges they always found a way forward.
Slark Labs delivered exceptional work throughout our engagement. Communication was excellent, and when given feedback they came back with everything addressed. A development partner you can rely on.
Slark Labs are great problem solvers, willing to try new approaches and always take client feedback on board to find the right solution.
Real solutions for real business challenges
Here's a glimpse of what ongoing partnership looks like in practice. Full case studies and client references available upon request.
Long-term white-label development partnership with a US-based digital agency. We serve as their invisible dev team across multiple client sites — handling builds, migrations, integrations and ongoing maintenance under their brand.
Discuss a similar build10+
client sites delivered
$1.2M
raised at one campaign event
1+ year
ongoing partnership
Results: 10+ client sites delivered, $1.2M raised at a single campaign event, and a 1+ year ongoing partnership as the agency's invisible development team.
Long-term development partner for a growing content creation platform, building and maintaining the core technology that powers thousands of daily user interactions across multiple markets.
Discuss a similar build6+ years
ongoing partnership
1,000+
daily active users
Europe
multiple markets served
Results: 6+ year ongoing development partnership supporting 1,000+ daily active users across multiple European markets.
Built internal tooling for an investment banking platform to automate financial reporting workflows, replacing manual processes with structured, automated pipelines.
Discuss a similar build3
Office.js integrations delivered
MVP
in final development stage
Investment banking
operations tooling
Results: Three Office.js integrations delivered for an investment banking operations team, with the MVP in its final development stage.
Full-stack development for a multi-tenant platform serving small businesses, handling everything from core product features to payment processing and custom domain management.
Discuss a similar build30+
paying customers
MVP → Launch
delivered end to end
Ongoing
feature development & support
Results: 30+ paying customers acquired with end-to-end delivery from MVP through launch, plus ongoing feature development and support.
Flexible engagement models built for agencies and product teams
Choose ongoing capacity, focused sprints, or fixed-scope projects — all with transparent numbers and month-to-month flexibility where it applies.
Looking for a partner tailored to your stack or stage? Start on the page that fits best.
White-label WordPress development, WooCommerce, and ongoing maintenance under your brand.
Learn moreCustom HubSpot apps, CMS themes, integrations, and marketplace builds for partner agencies.
Learn moreFractional dev team for MVPs, production rescues, and ongoing feature development.
Learn moreStraight answers on fit, scope, and how we work—so you can decide faster with less back-and-forth.
We mainly work with startups, product teams, and agencies that need reliable external development support. We are best suited for teams that already know what they need built and want a dependable partner to execute.
We are a strong fit for SaaS products, dashboards, internal tools, feature development, white-label client delivery, and ongoing product support.
Yes. We support agencies as a white-label development partner and can fit into existing workflows where needed.
Yes. Many of our engagements continue as monthly retainers for improvements, fixes, and future feature work.
Retainers are month-to-month. Cancel anytime with 14 days notice before your next billing cycle. No lock-ins, no penalties.
Yes. We can step into existing products, improve systems, ship features, and support ongoing releases.
Retainers start at $2,800/month, sprints from $5,000, and fixed projects from $5,000 depending on scope. See our full pricing page for tier details — every engagement still starts with a discovery conversation and a specific estimate before work begins.
If you have a defined build, a backlog that needs velocity, or a team that needs a dependable extension—let's talk this week. Clear scope, direct communication, and delivery you can plan around.
Prefer email only? Same inbox—mention your timeline and what you need built.