Developer Builds Battery-Efficient Geofencing App to Auto-Silence Phone by Location

·1 views

A developer created an Android app called Muffle to automatically manage phone sound profiles based on the user's location, inspired by an embarrassing notification during a funeral. The app uses Android's GeofencingClient API instead of continuous GPS polling, allowing the operating system to handle location monitoring at the hardware level and preserve battery life. Geofence boundary crossings trigger a BroadcastReceiver, keeping the app dormant until the user enters or exits a defined zone. The developer encountered challenges including GPS signal drift inside buildings, which caused erratic profile toggling, and solved it by implementing a dwell-time delay before confirming a transition. The project highlights key architectural trade-offs Android developers face when building location-aware background utilities.

Read the full story at DEV Community

This is an AI-generated summary. ShortSingh links to the original source for the complete article.

Discussion (0)

Gulf Bank Builds Fully Self-Hosted RAG Pipeline on Existing GPUs for Under $4,000

A Gulf-based bank required that all data, including loan-approval documents and AI queries, remain entirely on-premises due to strict compliance policies, ruling out any cloud API usage. An engineer built a complete Retrieval-Augmented Generation (RAG) pipeline using two GPU servers already sitting in the bank's server room. The full system, covering local embeddings, a self-hosted vector store, and an on-device language model, went live within seven weeks. The hardware setup consisted of two used NVIDIA 3090 GPUs, 64 GB of RAM, a 4 TB NVMe drive, and a 12-core CPU, with total hardware costs coming in under $4,000. The project highlighted that self-hosted RAG is more accessible than commonly assumed, with modest hardware capable of running a 13B-parameter model for internal use cases.

0 comments Read more at DEV Community

ProgrammingDEV Community ·

Key Architectural Challenges in Building Claude-Based AI Systems Explained

Developers working with Claude face recurring architectural pitfalls that can undermine reliability and security in AI-powered applications. One major challenge involves lossy summarization, where critical information is lost over time, which can be addressed by maintaining immutable state ledgers instead of relying on the model's memory. Another common issue is the over-reliance on prompt instructions to enforce business logic, which the model can potentially bypass or misinterpret. The recommended solution is code-level enforcement through middleware or PreToolUse hooks that apply deterministic validation rules before any tool payload reaches an external API or database. This defense-in-depth approach ensures that constraints like transaction limits remain outside the model's influence entirely.

0 comments Read more at DEV Community

ProgrammingDEV Community ·

Why Using Postgres as a Message Queue Can Become a Costly Single Point of Failure

Using PostgreSQL as a message queue alongside your primary database is increasingly common due to its simplicity, but engineers warn it creates a dangerous single point of failure. Postgres's MVCC architecture generates a new row on every update, meaning high-frequency queue operations cause table bloat, index fragmentation, and autovacuum lag that degrades the entire database. A 2023 benchmark found Postgres-as-a-queue handled roughly 660 messages per second, compared to RabbitMQ's 25,000 — nearly 40 times faster under identical conditions. When a queue backlog builds up, it puts backpressure on the database, creating a feedback loop where queue failure and database failure become the same incident, as highlighted in a 2021 AWS architecture post. Dedicated queueing solutions like Amazon SQS offer far greater throughput and fault isolation, keeping application and queue concerns cleanly separated.

0 comments Read more at DEV Community

ProgrammingDEV Community ·

STEM Project: Build an Aircraft Monitor Using Open ADS-B Data and an API

A STEM tutorial published on DEV Community guides students and developers in building a real-time aircraft monitoring system using the ADSBiq API and open ADS-B flight data. The project combines programming, GIS, and real-time systems, allowing users to query nearby aircraft by geographic coordinates via a simple Python script. A sample dataset of 100,000 observations from the Caribbean region, dated June 29, 2026, is publicly archived on Zenodo for analysis using tools like DuckDB, Polars, or PostGIS. Possible project outcomes include regional air traffic dashboards, altitude activity maps, and coverage experiments across terrain types such as coastlines, mountains, and rainforests. The author, who discloses an affiliation with ADSBiq, also invites feedback from Latin American educators and technical communities to expand Spanish-language resources for countries including Colombia, Peru, Chile, and Argentina.

0 comments Read more at DEV Community