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3,240 articles, newest first · page 36 of 54. For subject-based browsing use topics; for keyword lookup try search. Dates shown are assigned archive dates that order the library; they are not historical publication records.

2024
Dec 3, 2024 Priority Queues for Dijkstra: Decrease-Key, Lazy Deletion, and Buckets The four practical queue designs behind the same greedy loop, what each costs per operation, and how integer weight bounds turn a comparison heap into an array of buckets. algorithms · intermediate
Dec 3, 2024 Software Transactional Memory: Logs, Validation, and Retry How a transaction records its reads and writes in a log, why validation must happen before commit, and what livelock looks like when two long transactions keep colliding. programming languages · advanced
Dec 3, 2024 Storage Keys and Region Boundaries in Multiprogrammed Batch How a four-bit key attached to every 2 KB block of storage lets one batch partition be protected from another, and what the key cannot protect. computing history · intermediate
Dec 3, 2024 Vacuum Horizons, Dead Version Collection, and Table Bloat How an engine decides that a row version can never be seen again, why one old snapshot stalls collection for an entire database, and what freezing does to the identifier space. databases · intermediate
Dec 2, 2024 PID Namespaces and the Special Status of PID 1 How PID numbers become per-namespace identifiers, why the first process in a new namespace cannot be killed from inside it, and how namespace teardown depends on that process exiting. operating systems · foundational
Dec 1, 2024 Gradient Noise Scale and Critical Batch Size How the ratio of gradient variance to gradient squared norm sets the batch size beyond which additional examples buy no reduction in steps, and why that ratio rises over training. deep learning · advanced
Dec 1, 2024 Intermediaries, Hop-by-Hop Fields, and the Via Chain How proxies, gateways, and tunnels differ, which fields an intermediary must consume rather than forward, and what forwarding does to message semantics. internet protocols · advanced
November
Nov 29, 2024 Containment Through Network Isolation at the Packet Layer Why disabling an account does not stop an intrusion, and how switch port filters, ACLs, and quarantine VLANs differ in what they actually block. security · intermediate
Nov 29, 2024 Rotations and the In-Order Sequence They Preserve How a single rotation rewires three pointers while keeping key order, why some violations need two rotations, and what a rotation cannot repair. data structures · foundational
Nov 29, 2024 Timer Clamping, Background Throttling, and Cooperative Yielding The integer arithmetic and nesting rules behind setTimeout, why intervals do not catch up, and how scheduler priority levels change when a callback runs. web platform · advanced
Nov 28, 2024 Amdahl, Gustafson, and the Fixed-Problem Fallacy Why the two scaling laws disagree, which quantity each holds constant, and how the choice of fixed time versus fixed problem size changes the predicted ceiling. algorithms · intermediate
Nov 27, 2024 Atomic File Replacement: rename, fsync, and the Directory Entry Why a save operation that overwrites in place is not crash-safe, what the rename trick guarantees, and which flushes must bracket it for the guarantee to hold. mobile computing · intermediate
Nov 27, 2024 Chomsky Normal Form and the CYK Table How rewriting a grammar so every rule is A to BC or A to a makes cubic-time recognition possible, and why the table is indexed by substrings rather than by derivation prefixes. computation theory · intermediate
Nov 27, 2024 From Image Manifest to Mounted Root Filesystem How a container image is assembled from a manifest, a config blob and ordered layer tarballs, and what the runtime does between pulling and exec. virtualization · foundational
Nov 26, 2024 Interleaving as an Online Evaluation Method Team-draft and balanced interleaving merge two rankings into one list, so that clicks on the result can be used to compare systems without relevance judgments. information retrieval · advanced
Nov 26, 2024 The LSM Write Path from Memtable to Sorted Run How an insert becomes a log record, a memtable entry, a flushed sorted file, and finally a merged run, and what each step costs in write amplification. databases · intermediate
Nov 25, 2024 Extent Trees and the Replacement of Indirect Block Maps What an extent record actually encodes, why the inode-sized root makes small files free of external metadata, and how the tree splits when a file fragments. filesystems · intermediate
Nov 25, 2024 Versioning Strategies and What a Version Number Promises How path, header, and media-type versioning differ in what they can express, why a version is a support commitment rather than a name, and when a new version beats a compatible change. software architecture · intermediate
Nov 23, 2024 Frame Budgets, Long Tasks, and Where Input Latency Comes From How the main thread allocates work to a frame, why a 50 ms task delays the next interaction by more than 50 ms, and which scheduling primitives actually yield. web platform · intermediate
Nov 23, 2024 How a Session Identifier Binds Requests to Server State What the opaque string in a session cookie actually denotes, how much entropy it needs, and why the identifier and the record it points at have separate lifetimes. backend systems · foundational
Nov 23, 2024 Removing Work Before Making It Faster Why eliminating an operation dominates optimizing it, how redundant computation and over-fetching hide in ordinary code, and what changes when work is removed rather than accelerated. performance engineering · intermediate
Nov 22, 2024 Alignment, O_DIRECT, and the Cost of Bypassing the Page Cache The alignment and size rules a direct I/O request must satisfy, which part of the page-cache path disappears and which remains, and the cases where the bypass loses rather than wins. performance engineering · intermediate
Nov 22, 2024 Back Navigation When the Two Platforms Disagree Android has a system back action with predictive gestures; iOS has an edge swipe owned by the navigation controller. Reconciling them means modelling history in the shared core and restoring it after process death. mobile computing · intermediate
Nov 22, 2024 Circuit Breaker State Machines and Half-Open Probing The three states, the counters that drive transitions, and why the half-open probe count is the parameter that decides whether a recovering dependency survives its own recovery. backend systems · intermediate
Nov 22, 2024 Reference Monitors and Complete Mediation in Access Control Why an access check only means something if every access passes through it, how the policy decision point is separated from the enforcement point, and where check-then-use gaps appear. security · foundational
Nov 22, 2024 Retention Versus Reinitialisation in Deep Sleep The trade between keeping state alive across a sleep and rebuilding it on wake, expressed as a sleep-current penalty against a per-wake energy cost. embedded systems · advanced
Nov 22, 2024 Serialization Delay and the Cost of Small Packets Why shrinking packets reduces queueing delay but raises packet rate, header overhead, and per-packet forwarding cost, and where the crossover sits. networking · intermediate
Nov 21, 2024 Proof Terms: Reading a Derivation as a Program The correspondence between natural-deduction proofs and typed lambda terms, why normalisation is evaluation, and which logical principles correspond to which programming constructs. computation theory · foundational
Nov 20, 2024 Polynomial Time and the Machine-Independence of P How P is defined by counting steps on a Turing machine, why the class survives a change of machine model, and where the definition stops matching the idea of tractability. computation theory · foundational
Nov 19, 2024 Interval DP: Choosing the Last Operation Instead of the First Why splitting a contiguous range at its final split point turns exponential enumeration into an O(n cubed) table, and how the quadrangle inequality later removes a factor of n. algorithms · intermediate
Nov 19, 2024 Load Balancer Session Affinity and Its Failure Modes How sticky routing is implemented at layer 4 and layer 7, why consistent hashing limits the damage of a node loss, and which failures affinity cannot prevent. backend systems · intermediate
Nov 19, 2024 NAT, Port Overloading, and the Address Exhaustion Boundary How one public address serves many private hosts through port translation, what the binding table must store, and which protocol assumptions a translator cannot preserve. computing history · advanced
Nov 18, 2024 Configuration Graphs and Savitch's Reachability Argument How a nondeterministic space-bounded computation becomes a path problem in a configuration graph, and why reachability composes into a quadratic blowup in space rather than an exponential one. computation theory · intermediate
Nov 18, 2024 Leader Election, Leases, and What Quorum Protects Against Why a control plane needs a single active writer, how lease-based election bounds the overlap window, and where the underlying consensus store changes the guarantee. virtualization · advanced
Nov 18, 2024 Readiness Notification: What select, poll, and epoll Actually Report All three interfaces answer the same question about whether an operation would block, but they differ in how much work the kernel does per call and in what a returned descriptor guarantees. systems programming · foundational
Nov 18, 2024 Type Feedback and Inline Caches in Dynamic Call Sites How a runtime records which types actually reach a polymorphic operation, how an inline cache turns that history into a few comparisons, and why monomorphic feedback changes what the compiler can generate. language runtimes · intermediate
Nov 15, 2024 Pointer Events: Capture, Coalescing, and the Hit-Test Boundary A pointer stream follows one device from down to up, and capture replaces hit testing as the routing rule while coalescing hides the samples the browser merged into a frame. web platform · intermediate
Nov 15, 2024 Read Repair and Hinted Handoff on the Write Path How leaderless stores bring lagging replicas forward without a full scan, why hinted handoff is a temporary buffer rather than a repair, and where each mechanism fails under sustained failure. distributed systems · intermediate
Nov 14, 2024 Lockfiles, Hash Pinning, and Reconstructed Environments How a resolved dependency graph is recorded with content hashes, what the installer guarantees on a rebuild, and where the reconstruction stops being faithful. scientific computing · intermediate
Nov 14, 2024 Short-Circuit Evaluation as a Language Guarantee How && and || guarantee operand order, why that guarantee is a control-flow construct rather than an optimisation, and what nullable and optional chaining borrow from it. programming languages · intermediate
Nov 13, 2024 Channels, Dies, and Planes: How a Flash Controller Reaches Its Throughput A single flash die serves one operation at a time, so drive throughput comes from concurrency across channels and planes; the arithmetic of that concurrency sets the queue depth a workload needs. hardware engineering · advanced
Nov 13, 2024 The Crossover Between an Index Scan and a Sequential Scan Why fetching a few percent of a table by index can cost more than reading all of it, how physical correlation moves the crossover point, and what bitmap scans change. databases · foundational
Nov 13, 2024 The TCP/IP Split and the End-to-End Argument Why reliability moved out of the network and into the endpoints, what that costs in duplicated work, and how the argument constrains where a function may legally live. computing history · intermediate
Nov 12, 2024 Clock Sources and the Resolution Floor of a Timing Call How monotonic clocks, TSC reads, and syscall-based time differ in cost and granularity, why a measured interval is a difference of two uncertain readings, and how the floor limits what a benchmark can resolve. performance engineering · foundational
Nov 12, 2024 Cross-Modal Alignment and the Modality Gap Contrastive training can put matching images and text close together while the two modalities still occupy separate regions of the space; what produces that gap and what it costs for retrieval and composition. deep learning · advanced
Nov 12, 2024 Latches, Flip-Flops, and What Edge Sensitivity Actually Means How a cross-coupled pair stores a bit, why a master-slave arrangement turns level sensitivity into edge triggering, and what transparency costs downstream. hardware engineering · intermediate
Nov 11, 2024 Cancellation Points and the Half-Finished Cleanup State How asynchronous cancellation, unwinding, and cooperative cancellation interact with cleanup code, and why a cleanup routine must be reentrant against itself. systems programming · advanced
Nov 10, 2024 Physical Modularity: Compilation Firewalls and Rebuild Cost How declaration-level dependencies turn a header edit into a full rebuild, what a pimpl or interface boundary costs at runtime, and how package compilers avoid the same trap. software architecture · intermediate
Nov 8, 2024 Cholesky Factorization as a Positive-Definiteness Test Why the symmetric factorization needs no pivot search, where the factor-of-two saving comes from, and how a failed square root becomes a definiteness verdict. scientific computing · foundational
Nov 8, 2024 Exception Unwinding: Table-Driven Cleanup and the Cost of Try How a raise becomes a search through per-function tables, why some runtimes walk the stack twice, and what the zero-cost claim about exceptions really means. programming languages · advanced
Nov 8, 2024 Reduction Trees and What Associativity Buys Why a reduction needs an associative operator to be reordered, how tree shape changes floating-point results, and what error bounds the shapes imply. algorithms · foundational
Nov 7, 2024 Metadata-Only Journaling and the Three ext3 Data Modes What the data=journal, data=ordered, and data=writeback modes each guarantee about file contents after a crash, and why the ordered mode costs a dependency the other two avoid. filesystems · foundational
Nov 7, 2024 The Hidden Terminal Problem and Why 802.11 Reserves the Medium Why listening before transmitting fails on radio, how RTS/CTS and the duration field build a virtual carrier sense, and what the reservation costs per frame. networking · foundational
Nov 6, 2024 Change Coupling Mined from Version History Treating each commit as a set of files, computing co-change rates and lift over a window, and using the result to find coupling that no import graph can see. software architecture · intermediate
Nov 6, 2024 Stackful and Stackless Coroutines: Where Suspension Is Allowed A stackful coroutine can suspend inside any call; a stackless one can only suspend where the compiler emitted a resume point. The difference is a per-task stack versus a state machine, and it decides which libraries a task may call. language runtimes · intermediate
Nov 5, 2024 Backpressure and Deadlock in Long-Running Pipelines Why a blocking pipe is the only flow control a Unix pipeline has, how barrier stages stall it, and when a bounded queue beats a chain of processes. developer tools · advanced
Nov 5, 2024 Prefix Codes, the Kraft Inequality, and Why Huffman Is Optimal How decodability without separators constrains code lengths, what the Kraft sum measures, and the exchange argument that makes Huffman coding the best prefix code for a known distribution. computation theory · foundational
Nov 5, 2024 Replacement Without Exact LRU: Reference Bits and Clock Hands Why a cache cannot maintain a true LRU stack at speed, how one reference bit per line and a rotating hand approximate it, and where the approximation picks the wrong victim. memory systems · intermediate
Nov 4, 2024 Classful Addressing, Subnets, and the Move to CIDR Why the fixed class A, B, and C boundaries wasted most of the IPv4 space, how subnetting borrowed host bits, and what prefix aggregation changed about routing. computing history · intermediate
Nov 4, 2024 Structured Result Cards and the Schema That Feeds Them How a search interface renders a recipe, event, or product as a structured card rather than a text snippet, and how the structured data gets from a page into the index. information retrieval · advanced

2024

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