Here’s a concise, curated list of reputable Sri Lankan companies that commonly deliver enterprise-grade mobile solutions (mobile apps, mobile backends/APIs, telco integrations, mobile‑workforce tooling, IoT/mobility platforms and enterprise mobility services). Short note of each firm’s strength and a source you can check.

Top picks (not exhaustive)

• Virtusa — large global IT services & digital‑transformation shop with major engineering capacity in Sri Lanka (mobile, cloud, UX, enterprise modernization). (virtusa.com)
• 99X Technology — product‑engineering specialist (high quality full‑stack & mobile product teams serving enterprise/ISV customers). (99x.io)
• WSO2 — enterprise middleware/API/identity vendor (widely used for mobile backends, telco APIs and integration platforms). (wso2.com)
• Fortude — enterprise digital & ERP integration specialist (cloud/native app work and enterprise application integrations). (en.wikipedia.org, linkedin.com)
• Calcey — boutique product engineering & enterprise mobile solutions (Agile product teams, ISO/SEC certifications, enterprise clients). (lk.linkedin.com, businesscafe.lk)
• Zone24x7 — engineering + R&D firm that blends embedded/IoT and software (good for mobile + device/IoT enterprise solutions). (zone24x7.com, srilankabusiness.com)
• MillenniumIT ESP (MIT ESP) — enterprise solutions provider (systems integration, omnichannel & mobile enablement for large enterprises). (mitesp.com, en.wikipedia.org)
• hSenid (hSenid / hSenid Mobile) — HR and telco/mobile platform specialist (mobile apps, USSD/SMSC, telco API platforms, enterprise mobile services). (hsenid.com, srilankabusiness.com)
• Sysco LABS — captive engineering/innovation centre (enterprise‑grade platforms and mobile services for a Fortune‑scale organization). (syscolabs.lk, srilankabusiness.com)
• Dialog Axiata (Dialog Enterprise) — major telco with enterprise mobility, SD‑WAN, IoT and mobile workforce solutions for businesses. (business.dialog.lk)
• SLTMobitel / SLT (Mobitel) — national telco offering mobile enterprise services, mobile‑money and connectivity solutions for enterprises. (en.wikipedia.org)
• Calibre or local specialists on Clutch (examples: Developer Bazaar, VLink, Elysian Techlabs) — good mid‑market mobile app shops for faster, cost‑effective enterprise apps; see Clutch Sri Lanka app‑developer rankings. (clutch.co)

Quick selection checklist (how to pick from the list)

• Match expertise to your need: product engineering vs systems integration vs telco integration vs IoT/hardware.
• Verify enterprise experience: ask for case studies on scale, security (ISO 27001, SOC2), and integrations (SSO, API gateways).
• Team model & location: do you need a dedicated on‑site team, ODC, or project delivery from Sri Lanka?
• Budget & timeline: product engineering houses (99X, Calcey) vs large integrators (Virtusa, Fortude, MillenniumIT) differ in rates and scale.
• Do a 6–8 week pilot/proof‑of‑concept to validate fit before full rollout.

If you want, I can:

• shortlist 3 firms from the above tailored to a specific use case (e.g., B2B mobile field app, customer‑facing mobile wallet, telco API integration) and summarize strengths + likely cost/timeline ranges.