I build mobile apps & AI systems that scale to millions.
Hi, I'm Nik — an Upwork Top Rated Plus senior mobile fullstack engineer. I design, build, and ship high-retention Native iOS (Swift/SwiftUI), Flutter apps, and On-Device AI / LLM Agents. My work powers products trusted by 100M+ users, including contributions to Credit Karma and ConfirmTkt.
Next-gen creator streaming platform engineered & launched solo from zero.
Build next-generation AI-powered mobile applications
I combine modern mobile development with practical on-device intelligence, custom multi-modal LLM agents, and real-time streaming interfaces.
On-Device Privacy & Vision AI
Run fast machine learning models directly on iPhone and iPad with zero network latency, offline capability, and 100% user data privacy.
GPT-4o & Claude 3.5 Integrations
Smart conversational copilots, context-aware RAG pipelines, and automated text/image generation embedded natively into your mobile UI.
Voice Agents & Real-Time Audio
Sub-second voice-to-voice interfaces, Whisper speech transcription, and ultra-realistic voice synthesis for assistants and accessibility.
Everything needed to turn specs into live products
From initial architecture and Figma conversion to cloud API engineering and App Store approvals, I handle the full technical lifecycle.
Native iOS Development
High-performance, fluid iPhone & iPad applications built with Swift and SwiftUI/UIKit. Strict adherence to Apple Human Interface Guidelines.
- 0 to 1 full product builds from Figma designs
- Smooth 120Hz ProMotion animations & widgets
- Complete App Store submission & review support
Flutter & Cross-Platform
A single clean codebase running natively on iOS and Android. Cuts development and maintenance costs up to 40% with zero lag.
- Fast-to-market MVP builds for startups
- Clean Bloc & Riverpod state architecture
- Native device bridges (camera, BLE, biometrics)
Fintech & Subscriptions
Bank-grade payment integrations where zero errors are tolerated. Seamless in-app purchases, Apple Pay sheets, and recurring billing.
- Apple Pay & Google Pay native checkout
- Stripe, Razorpay, and tokenized cards
- StoreKit 2 auto-renewing subscriptions
Cloud Backends & APIs
The fast, secure cloud engine behind your app. Real-time databases, user authentication, automated push notifications, and data synchronization.
- Fast Node.js & Express REST APIs
- Firebase Firestore rules & Cloud Functions
- Automated push notifications & background queues
AI Mobile Integrations
Incorporate practical AI features that deliver real business value. On-device Core ML, OpenAI GPT-4o, and Claude 3.5 integrations.
- Smart chatbots and content generator workflows
- On-device image recognition with Apple Core ML
- Voice-to-text and streaming AI response feeds
MVP Scoping & Code Audits
Direct advisory before you spend capital. Honest breakdown of native vs. Flutter, third-party vendor selection, and realistic milestone scoping.
- Clear technical feasibility & milestone roadmaps
- Codebase audits to fix crashes and performance lag
- App Store rejection resolution and compliance fixes
Get an instant timeline & cost estimate
Select your platform and features to calculate estimated development sprints and a ballpark quote.
Top products built & shipped to stores
A visual preview of top flagship applications across fintech, SaaS, travel, security, and streaming.
Credit Karma
Nationwide personal finance and credit monitoring app. Maintained critical credit score visualization flows and real-time push alert listeners for 50M+ users.
ConfirmTkt
Official IRCTC partner train discovery & booking app. Built waitlist probability prediction UI, battery-efficient live GPS train running status, and instant Tatkal checkouts.
Time Clock Wizard
US enterprise workforce management platform. Engineered GPS geofenced clock-in, facial verification check-in, overtime calculators, and offline background sync queues.
Inflixo AI
Full-scale content creator streaming platform with AI automated monetization. Conceived, architected, and built solo — from video transcoder pipelines to subscription checkouts.
How I solve complex engineering challenges
Real-world breakdowns of the client problem, the technical solution I implemented, and the measurable business outcome.
Credit Karma — High Scale Financial Visualizations
Displaying complex multi-bureau credit reports and historical score progressions without UI lag across millions of devices.
- Optimized declarative SwiftUI chart renderers
- Efficient memory caching for score progression feeds
- Strict end-to-end data encryption in transit
Maintained 60+ FPS fluid rendering with 99.99% crash-free stability under heavy nationwide traffic spikes.
Direct engineering expertise, no agency overhead
You are not hiring an agency where your project gets passed around to junior trainees. You talk directly with the senior developer building your product.
Direct Senior Collaboration
No project managers in the middle, no miscommunication. You get straight answers, rapid iterations, and direct access to the engineer writing the code.
High-Stakes Experience
I have built apps managing real financial transactions and confidential user data. You get enterprise security, strict data protection, and audited code quality.
Long-Term Reliability
My longest ongoing client partnership is over 4 years. I don't disappear after your first release — I stay to support your growth, updates, and scaling.
Modern technologies chosen for stability & speed
I use industry-standard, well-supported technologies to ensure your app is future-proof, easy to maintain, and fast.
What founders & CTOs say about working with me
Real feedback from clients across the United States, Europe, and worldwide.
"Nick is an outstanding iOS developer. He delivered a clean, fast, and reliable app. We're thrilled with the results and look forward to future collaborations."
"Nick was a key contributor, delivering high-quality work on time. His insights greatly improved our product. I look forward to working with him again."
"Nick delivered excellent work within budget and on time. His communication and documentation were top-notch. I look forward to future projects."
Everything you need to know before hiring
Clear answers on contracts, Upwork collaboration, AI capabilities, App Store guarantees, and project timelines.
When you hire an agency, you pay high overhead and your project is frequently assigned to junior developers. When you work with me, you collaborate directly with an Upwork Top Rated Plus senior engineer with 9+ years of experience who has shipped 50+ production apps for 100M+ users. You get direct accountability, faster sprints, and clean code.
Yes. You have total flexibility. If you prefer the security of platform escrow and verified time tracking, you can hire me directly on Upwork where I maintain a Top Rated Plus badge and 100% Job Success Score. Alternatively, for US/UK corporate clients, I offer direct fixed-price or monthly retainer contracts.
Yes. I integrate on-device Apple Core ML, custom multi-modal LLM pipelines (OpenAI GPT-4o, Claude 3.5), speech-to-speech agents (Whisper), and computer vision models directly into iOS and Flutter apps with real-time responsive interfaces.
Yes. Having shipped over 50 apps, I handle all provisioning certificates, privacy manifest rules, store compliance audits, and directly resolve any reviewer questions until your app is live.
You retain 100% ownership of all source code and IP. I sign standard NDAs prior to discovery, and all development occurs in private Git repositories transferred directly to you.
An engineer with a founder's mindset
I'm Nik, an independent mobile & AI fullstack engineer based in Ahmedabad, India. For over 9+ years in tech, I've partnered directly with founders, startups, and product managers across the US, UK, and Europe.
I currently work as the sole mobile developer for UK-based company Eviid, hold a continuous 4+ year partnership with US SaaS company Time Clock Wizard, and built creator platform Inflixo AI from scratch.
Tell me about your project
Tell me what you are looking to build, your target launch date, or budget. I'll provide an honest assessment, architectural recommendations, and a transparent quote. I usually respond within 4 hours.
Send a Quick Project Brief
Share your requirements and receive a free quote and timeline estimate within 4 hours.