"
CTO, NexaFinance Ltd.
The architecture MC CALLY delivered was not only scalable but exceptionally clean and documented. We onboarded three new engineers in a week with zero confusion.
Encrypted Communication Channel
Scaling your vision into global reality
Our senior architects are ready to review your infrastructure and provide a strategic technical roadmap within 24 hours. No auto-replies — a real engineer responds to every message with substance and precision.
Headquarters Intel
We operate globally with a distributed engineering team. Our headquarters in Barcelona serves as the strategic and operational nerve center for all client engagements worldwide.
Company
MC CALLY
Email
mccalvinarvilla@gmail.com
Address
Calle Provença 167, 5-5
Barcelona, 08036 — Spain
Barcelona, 08036 — Spain
D-U-N-S® Number
563662907
Phone
+44 7436 758 207
Send a Message
Fill in the details below and a senior engineer will reach out within 2 business hours. No sales calls — just a direct, technical conversation.
Client Testimonials
What Our Partners Say
"
Founder, OrbitalSaaS
From the first call, I was speaking directly with architects — not account managers. They diagnosed a critical performance bottleneck in our pipeline within two days of engagement.
"
VP Engineering, Sentinel Health
Security was our biggest concern with HIPAA compliance. MC CALLY built an airtight encryption layer and documented every decision so we could pass our audit without a single finding.
"
CEO, Quantum Retail Group
We went from 2,000 to 400,000 concurrent users in six weeks after a product feature went viral. The infrastructure MC CALLY built didn't even flinch — uptime held at 99.97%.
"
Product Lead, Vega Logistics
Multi-region deployment across four continents felt overwhelming until MC CALLY mapped it into a clean architecture diagram and a 12-week delivery plan. They delivered in 11.
"
Head of Data, PulseAnalytics
Their free preliminary audit saved us from a $200k architecture mistake. That level of transparency before a single contract was signed is what makes MC CALLY genuinely different.
Frequently Asked Questions
How quickly can you start work after we sign an agreement?
For projects that have passed our initial technical audit, we can typically assign a dedicated senior engineer within 48 to 72 business hours of contract execution. For larger engagements requiring a full team, we schedule a structured onboarding sprint in the first week to align on architecture, tooling, and communication cadence.
Do you work with early-stage startups or only established companies?
We work across the full company lifecycle — from pre-seed founders with a napkin sketch to Series-C companies refactoring legacy systems. What matters to us is not your funding stage, but the clarity of your technical vision and the seriousness of your intent to build something durable. Our free preliminary audit is specifically designed to give early-stage teams an honest picture of scope and cost before they commit.
What happens if we need to scale the team mid-project?
Our engagement model is built for elasticity. If your product gains traction faster than expected — or if a new feature requires specialized expertise — we can expand your team without disrupting the existing workflow. Because our engineers share the same architectural standards and code review protocols, onboarding additional capacity takes days, not weeks.
Is source code ownership transferred to us upon project completion?
Absolutely. All intellectual property — including source code, documentation, database schemas, and design assets — is transferred in full to you upon final delivery and payment. Our contracts are written explicitly to protect your ownership. We retain zero rights to reuse or repurpose any element of your proprietary codebase for other clients.
What tech stacks do you specialize in?
Our core stack spans Flutter and React Native for cross-platform mobile, Swift and Kotlin for native iOS and Android, React and Next.js on the frontend, and Python or Node.js for backend services. Infrastructure is AWS-native by default, with Terraform for IaC. We can accommodate other stacks, but we will always be transparent about where our deepest expertise lies rather than overpromising.
How do you handle post-launch support and maintenance?
We offer structured retainer agreements that cover monitoring, hotfix SLAs, dependency updates, and proactive performance audits on a monthly or quarterly basis. Every post-launch retainer includes direct access to the same engineers who built the system — not a separate support team unfamiliar with your codebase. Response time for critical production incidents is guaranteed under 2 hours.